sof-hda-dsp: make Headphone Playback Switch conditional

[GitHub pull_request - opened]

alsa-project/alsa-ucm-conf pull request #34 was opened from kv2019i:

The Headphone Playback Switch control is not present in all
HDA codecs. Allow the Headphones definition to work also on
such systems.

Signed-off-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>

Request URL   : https://github.com/alsa-project/alsa-ucm-conf/pull/34
Patch URL     : https://github.com/alsa-project/alsa-ucm-conf/pull/34.patch
Repository URL: https://github.com/alsa-project/alsa-ucm-conf