ALSA: hda - Use always amps for auto-mute on AD1986A codec

It seems that AD1986A cannot manage the dynamic pin on/off for
auto-muting, but rather gets confused.  Since each output has own amp,
let's use it instead.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=64971
Cc: <stable@vger.kernel.org> [v3.11+]
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/patch_analog.c

@@ -361,6 +361,9 @@ static int patch_ad1986a(struct hda_codec *codec)
 	 */
 	spec->gen.multiout.no_share_stream = 1;
 
+	/* AD1986A can't manage the dynamic pin on/off smoothly */
+	spec->gen.auto_mute_via_amp = 1;
+
 	snd_hda_pick_fixup(codec, ad1986a_fixup_models, ad1986a_fixup_tbl,
 			   ad1986a_fixups);
 	snd_hda_apply_fixup(codec, HDA_FIXUP_ACT_PRE_PROBE);