ALSA: hda/realtek - Fix lose hp_pins for disable auto mute

When auto_mute = no or spec->suppress_auto_mute = 1, cfg->hp_pins will
lose value.

Add this patch to find hp_pins value.
I add fixed for ALC282 ALC225 ALC256 ALC294 and alc_default_init()
alc_default_shutup().

Signed-off-by: Kailang Yang <kailang@realtek.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>