ALSA: ice1712: Add support for STAudio ADCIII

STAudio ADCIII has the same SSID as Hoontech STDSP24, but requires a
slightly different configuration.  This patch allows user to choose
this model via model=staudio option to set the proper configuration
for the board.

Bugzilla: http://bugzilla.suse.com/show_bug.cgi?id=1048934


Signed-off-by: Takashi Iwai <tiwai@suse.de>