[ALSA] hda: fix Mic in as output

Some laptop has an internal analog microphone that is 'fixed'.
This patch prevents creating a 'Mic In as Output' switch for
ports that can't be outputs.

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