CA0132 driver had some codes to handle the S/PDIF I/O, but the actual
setups of pins and converters were missing.  Now the pins are added.

Also, fixed a few points triggering invalid codec verbs and mixer
elements since the digital I/O audio widgets on CA0132 have no amp.
Signed-off-by: Takashi Iwai <tiwai@suse.de>