ALSA: hda - Add missing check of pin vref 50 and others in Realtek codecs

Some Realtek codecs like ALC861 seem to support only VREF50 while the
current driver assumes it's only VREF80.  Check other VREF bits to set
the correct value.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index bcbb736..0fd258e 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -776,6 +776,12 @@
 		pincap = (pincap & AC_PINCAP_VREF) >> AC_PINCAP_VREF_SHIFT;
 		if (pincap & AC_PINCAP_VREF_80)
 			val = PIN_VREF80;
+		else if (pincap & AC_PINCAP_VREF_50)
+			val = PIN_VREF50;
+		else if (pincap & AC_PINCAP_VREF_100)
+			val = PIN_VREF100;
+		else if (pincap & AC_PINCAP_VREF_GRD)
+			val = PIN_VREFGRD;
 	}
 	snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_PIN_WIDGET_CONTROL, val);
 }