ucm2: common: pcm: Add hdmi.conf to handle the creation

ucm2: common: pcm: Add hdmi.conf to handle the creation

User space expect to see hdmi: PCM devices to be able to use bytestream
passthrough.

The common/pcm/hdmi.conf provides two macros:
HdmiPCM: to generate an ALSA conf section for an hdmi: PCM device
HdmiPCMSave: to save the generated config

Example of use (sof-hda-dsp card with hardware HDMI PCMs: 3-5):
Macro.0.HdmiPCM { Device 3 Index 0 }
Macro.1.HdmiPCM { Device 4 Index 1 }
Macro.2.HdmiPCM { Device 5 Index 2 }
Macro.3.HdmiPCMSave { }

Closes: https://github.com/alsa-project/alsa-ucm-conf/pull/411
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>