To allow multiple PCM devices to be registered for the LPE audio card,
split the private data into card and PCM specific chunks. For now we'll
stick to just one PCM device as before.

v2: Rework to do a pcm device per port instead of per pipe

Cc: Takashi Iwai <tiwai@suse.de>
Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170427160231.13337-11-ville.syrjala@linux.intel.comReviewed-by: Takashi Iwai <tiwai@suse.de>