DisplayPort not listed as playback device. How can I add it?

I want to send my audio to the connected monitor on my displayport output. I use KDE on devuan. **I can play manually using aplay (see below), the device seems to just not be listed**, so I exclude driver issues. Using pactl I found the port which the monitor is connected (-> hdmi-output-1):

$ pactl list cards
...
Card #1
	Name: alsa_card.pci-0000_00_1f.3
	Driver: module-alsa-card.c
	Owner Module: 7
	Properties:
		alsa.card = "0"
		alsa.card_name = "HDA Intel PCH"
		alsa.long_card_name = "HDA Intel PCH at 0xdc240000 irq 136"
		alsa.driver_name = "snd_hda_intel"
		device.bus_path = "pci-0000:00:1f.3"
		sysfs.path = "/devices/pci0000:00/0000:00:1f.3/sound/card0"
		device.bus = "pci"
		device.vendor.id = "8086"
		device.vendor.name = "Intel Corporation"
		device.product.id = "9d71"
		device.product.name = "Sunrise Point-LP HD Audio"
		device.form_factor = "internal"
		device.string = "0"
		device.description = "Built-in Audio"
		module-udev-detect.discovered = "1"
		device.icon_name = "audio-card-pci"
	Profiles:
		input:analog-stereo: Analog Stereo Input (sinks: 0, sources: 1, priority: 65, available: yes)
		output:analog-stereo: Analog Stereo Output (sinks: 1, sources: 0, priority: 6500, available: yes)
		output:analog-stereo+input:analog-stereo: Analog Stereo Duplex (sinks: 1, sources: 1, priority: 6565, available: yes)
		output:analog-surround-40: Analog Surround 4.0 Output (sinks: 1, sources: 0, priority: 1200, available: yes)
		output:analog-surround-40+input:analog-stereo: Analog Surround 4.0 Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 1265, available: yes)
		output:hdmi-stereo: Digital Stereo (HDMI) Output (sinks: 1, sources: 0, priority: 5900, available: no)
		output:hdmi-stereo+input:analog-stereo: Digital Stereo (HDMI) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 5965, available: no)
		output:hdmi-surround: Digital Surround 5.1 (HDMI) Output (sinks: 1, sources: 0, priority: 800, available: no)
		output:hdmi-surround+input:analog-stereo: Digital Surround 5.1 (HDMI) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 865, available: no)
		output:hdmi-surround71: Digital Surround 7.1 (HDMI) Output (sinks: 1, sources: 0, priority: 800, available: no)
		output:hdmi-surround71+input:analog-stereo: Digital Surround 7.1 (HDMI) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 865, available: no)
		output:hdmi-stereo-extra1: Digital Stereo (HDMI 2) Output (sinks: 1, sources: 0, priority: 5700, available: yes)
		output:hdmi-stereo-extra1+input:analog-stereo: Digital Stereo (HDMI 2) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 5765, available: yes)
		output:hdmi-surround-extra1: Digital Surround 5.1 (HDMI 2) Output (sinks: 1, sources: 0, priority: 600, available: yes)
		output:hdmi-surround-extra1+input:analog-stereo: Digital Surround 5.1 (HDMI 2) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 665, available: yes)
		output:hdmi-surround71-extra1: Digital Surround 7.1 (HDMI 2) Output (sinks: 1, sources: 0, priority: 600, available: yes)
		output:hdmi-surround71-extra1+input:analog-stereo: Digital Surround 7.1 (HDMI 2) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 665, available: yes)
		output:hdmi-stereo-extra2: Digital Stereo (HDMI 3) Output (sinks: 1, sources: 0, priority: 5700, available: no)
		output:hdmi-stereo-extra2+input:analog-stereo: Digital Stereo (HDMI 3) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 5765, available: no)
		output:hdmi-surround-extra2: Digital Surround 5.1 (HDMI 3) Output (sinks: 1, sources: 0, priority: 600, available: no)
		output:hdmi-surround-extra2+input:analog-stereo: Digital Surround 5.1 (HDMI 3) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 665, available: no)
		output:hdmi-surround71-extra2: Digital Surround 7.1 (HDMI 3) Output (sinks: 1, sources: 0, priority: 600, available: no)
		output:hdmi-surround71-extra2+input:analog-stereo: Digital Surround 7.1 (HDMI 3) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 665, available: no)
		output:hdmi-stereo-extra3: Digital Stereo (HDMI 4) Output (sinks: 1, sources: 0, priority: 5700, available: no)
		output:hdmi-stereo-extra3+input:analog-stereo: Digital Stereo (HDMI 4) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 5765, available: no)
		output:hdmi-surround-extra3: Digital Surround 5.1 (HDMI 4) Output (sinks: 1, sources: 0, priority: 600, available: no)
		output:hdmi-surround-extra3+input:analog-stereo: Digital Surround 5.1 (HDMI 4) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 665, available: no)
		output:hdmi-surround71-extra3: Digital Surround 7.1 (HDMI 4) Output (sinks: 1, sources: 0, priority: 600, available: no)
		output:hdmi-surround71-extra3+input:analog-stereo: Digital Surround 7.1 (HDMI 4) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 665, available: no)
		output:hdmi-stereo-extra4: Digital Stereo (HDMI 5) Output (sinks: 1, sources: 0, priority: 5700, available: no)
		output:hdmi-stereo-extra4+input:analog-stereo: Digital Stereo (HDMI 5) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 5765, available: no)
		output:hdmi-surround-extra4: Digital Surround 5.1 (HDMI 5) Output (sinks: 1, sources: 0, priority: 600, available: no)
		output:hdmi-surround-extra4+input:analog-stereo: Digital Surround 5.1 (HDMI 5) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 665, available: no)
		output:hdmi-surround71-extra4: Digital Surround 7.1 (HDMI 5) Output (sinks: 1, sources: 0, priority: 600, available: no)
		output:hdmi-surround71-extra4+input:analog-stereo: Digital Surround 7.1 (HDMI 5) Output + Analog Stereo Input (sinks: 1, sources: 1, priority: 665, available: no)
		off: Off (sinks: 0, sources: 0, priority: 0, available: yes)
	Active Profile: output:analog-stereo+input:analog-stereo
	Ports:
...
		hdmi-output-1: HDMI / DisplayPort 2 (type: HDMI, priority: 5800, latency offset: 0 usec, available)
			Properties:
				device.icon_name = "video-display"
				device.product.name = "LC49G95T"
			Part of profile(s): output:hdmi-stereo-extra1, output:hdmi-stereo-extra1+input:analog-stereo, output:hdmi-surround-extra1, output:hdmi-surround-extra1+input:analog-stereo, output:hdmi-surround71-extra1, output:hdmi-surround71-extra1+input:analog-stereo
...

I can list and play a test sound using aplay (-> 0,7, which is hdmi 1 as found above):

$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC298 Analog [ALC298 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 7: HDMI 1 [HDMI 1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 8: HDMI 2 [HDMI 2]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 9: HDMI 3 [HDMI 3]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 10: HDMI 4 [HDMI 4]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
...

$ aplay -D plughw:0,7 /usr/share/sounds/alsa/Front_Center.wav
Playing WAVE '/usr/share/sounds/alsa/Front_Center.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono

And I do hear the sound coming from the monitor. So I'm only missing to activate/enable this port to make available in my kde audio manager, how can I do that?