ALSA: hda - Enable line-out detection only with speakers

Enable line-out detection for IDT/STAC codecs only when speaker pins
exist.  In some cases, the speaker itself is identified as line-out,
and this confuses the situation.  Only the extra line-outs should do
auto-muting.

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