ASoC: SOF: Intel: Create ptl.c as placeholder for Panther Lake features

Create a minimal placeholder to make it possible to add code to handle
the new features of Panther Lake compared to MTL/LNL.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://patch.msgid.link/20250307112816.1495-5-peter.ujfalusi@linux.intel.com


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