[ALSA] hda: Added STAC92HD73 support

Added support for new STAC92HD73 family of codecs. Additionally added
features for multiple analog loopbacks, and multiple dmux mixers.
Regression testing for the analog loopback changes for STAC9205 and
STAC9274D completed with any issues, as well for the dmux changes.

Signed-off-by: Matthew Ranostay <mranostay@embeddedalley.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>