ALSA: hda: digital slave support for IDT codecs

Added slave_dig_outs entries for several IDT codecs that have multiple
SPDIF outs, and enabled these SPDIF outs in several pin configs.

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