ALSA: hda - No 'Headphone as Line-out' swich without line-outs

STAC/IDT driver creates "Headphone as Line-Out" switch even if there
is no line-out pins on the machine.  For devices only with headpohnes
and speaker-outs, this switch shouldn't be created.

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