ASoC: hdac_hdmi: Move channel info from pin to PCM structure

Channel info is part of the pcm parameter and channel map control is
created for each pcm. So move channel info to pcm instead of pin
structure and the mutex lock to pcm.

Signed-off-by: Jeeja KP <jeeja.kp@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>