Manage the tags assigned for unsolicited events dynamically together
with the jack-detection routines.  Basically this is almost same as what
we've done in patch_sigmatel.c.  Assign the new tag number for each new
unsol event, associate with the given NID and the action type, etc.

With this change, now all pins looked over in snd_hda_jack_add_kctls()
are actually enabled for detection now even if the pins aren't used for
jack-retasking by the driver.

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