ALSA: hda - Use auto_mute_via_amp=1 for VT1708

We've got bug report wrt many machines with VT1708 (e.g. IBM POS
machines) showing the broken auto-mute behavior.  It turned out that
the problem is that the pin control values of the speaker and line-out
pins are completely ignored.  As a workaround, let's use the newly
introduced feature of the generic parser, to control the mute via amp
on pins.

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

sound/pci/hda/patch_via.c

@@ -741,6 +741,8 @@ static int patch_vt1708(struct hda_codec *codec)
 	/* don't support the input jack switching due to lack of unsol event */
 	/* (it may work with polling, though, but it needs testing) */
 	spec->gen.suppress_auto_mic = 1;
+	/* Some machines show the broken speaker mute */
+	spec->gen.auto_mute_via_amp = 1;
 
 	/* Add HP and CD pin config connect bit re-config action */
 	vt1708_set_pinconfig_connect(codec, VT1708_HP_PIN_NID);