ASoC: Intel: sof_hdmi: add common header for HDMI

Add a common header for Intel HDMI dai link (idisp) initialization.
Declare the sof_hdmi_private structure in machine driver private data
and use it to initialize dai link.

Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Brent Lu <brent.lu@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20231012190826.142619-13-pierre-louis.bossart@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>