ALSA: hda: add support for jack detection on IDT codecs.

This patch adds support to the IDT codec families to report jack status
to the jack abstraction layer. This required some reorganization in the
stac92xx_unsol_event function in which the index value is changed to
reporting the nid with the event.

Also adds an sigmatel_jack struct to keep track of the nid relation
to the jack abstraction layer instance. Also adds functions to set and
retrieve data values for each nid, this is used in stac92xx_unsol_event
to retrieve the GPIO mask for STAC_VREF_EVENT.

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