No HDMI audio device on intel_snd_hda (Ubuntu 20.04)
Update you BIOS - you are running version 1.0 and the current version is 1.4. You will have to do this manually since ASRock doesn't support the LVFS project.
If lshw lists a device as UNCLAIMED, then there is no driver loaded for this device. You can check this with lspci -nk -s 00:02.0 - the output should include Kernel driver in use:. Also your lshw output would show configuration: driver=<driver> latency=0
Try rmmod i915; modprobe -vvv i915 and check dmesg or /var/log/syslog. Since it appears you are running a mainline kernel, maybe try v5.14.