ALSA: hda - Add expose_enum_ctl flag to snd_hda_add_vmaster_hook()

Since it's not always safe to assume that the vmaster hook is purely the
mute-LED control, add the flag indicating whether to expose the mute-LED
enum control or not.  Currently, conexant codec sets this off for non-HP
laptops where EAPD may be used really as EAPD.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/patch_sigmatel.c b/sound/pci/hda/patch_sigmatel.c
index cd04e29..153b9ae 100644
--- a/sound/pci/hda/patch_sigmatel.c
+++ b/sound/pci/hda/patch_sigmatel.c
@@ -1166,7 +1166,7 @@
 
 	if (spec->gpio_led) {
 		spec->vmaster_mute.hook = stac92xx_vmaster_hook;
-		err = snd_hda_add_vmaster_hook(codec, &spec->vmaster_mute);
+		err = snd_hda_add_vmaster_hook(codec, &spec->vmaster_mute, true);
 		if (err < 0)
 			return err;
 	}