ALSA: hda - Fix IDT/STAC multiple HP detection

Due to the recent change for multiple HP as line-out switch, only
one of the multiple headphons (usually a wrong one) is toggled
and the other pins are still disabled.  This causes the silent output
problem on some Dell laptops.

Also, the hp_switch check is screwed up when a line-in or a mic-in
jack exists.  This is added as an additional output, but hp_switch
check doesn't take it into account.

This patch fixes these issues: simplify hp_switch check by using
the NID instead of bool, and clean up / fix the toggle of HP pins
in unsol event handler code.

Reference: Novell bnc#443267
	https://bugzilla.novell.com/show_bug.cgi?id=443267

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