ucm2: sof-soundwire: Use the HdmiDevice macro for hdmi device creation

ucm2: sof-soundwire: Use the HdmiDevice macro for hdmi device creation

The duplicated code for the hdmi device creation can be removed by using
the HdmiDevice macro.

The macro needs Syntax 7 to work (variable as parameter support), update
the Syntax version of the file as well.

Closes: https://github.com/alsa-project/alsa-ucm-conf/pull/413
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>