ALSA: sound/pci/hda: fix sparse warning: different signedness

Fix this sparse warning:
  sound/pci/hda/hda_codec.c:1544:19: warning: incorrect type in assignment (different signedness)
  sound/pci/hda/hda_codec.c:1544:19:    expected unsigned long *vals
  sound/pci/hda/hda_codec.c:1544:19:    got long *<noident>
Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/hda_local.h

@@ -136,7 +136,7 @@ extern struct hda_ctl_ops snd_hda_bind_sw;	/* for bind-switch */
 
 struct hda_bind_ctls {
 	struct hda_ctl_ops *ops;
-	long values[];
+	unsigned long values[];
 };
 
 int snd_hda_mixer_bind_ctls_info(struct snd_kcontrol *kcontrol,