ALSA: pci: constify snd_kcontrol_new structures

Declare snd_kcontrol_new structures as const as they are only passed as
an argument to the function snd_ctl_new1. This argument is of type
const, so snd_kcontrol_new structures having the same property can be
made const too.
Done using Coccinelle:

@r1 disable optional_qualifier @
identifier i;
position p;
@@
static struct snd_kcontrol_new i@p = {...};

@ok1@
identifier r1.i;
position p;
expression e1;
@@
snd_ctl_new1(&i@p,e1)

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct snd_kcontrol_new i;

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 9913be8..bf491eb 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -1897,7 +1897,7 @@ static int vmaster_mute_mode_put(struct snd_kcontrol *kcontrol,
 	return 1;
 }
 
-static struct snd_kcontrol_new vmaster_mute_mode = {
+static const struct snd_kcontrol_new vmaster_mute_mode = {
 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 	.name = "Mute-LED Mode",
 	.info = vmaster_mute_mode_info,
@@ -2637,7 +2637,7 @@ static int spdif_share_sw_put(struct snd_kcontrol *kcontrol,
 	return 0;
 }
 
-static struct snd_kcontrol_new spdif_share_sw = {
+static const struct snd_kcontrol_new spdif_share_sw = {
 	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 	.name = "IEC958 Default PCM Playback Switch",
 	.info = snd_ctl_boolean_mono_info,