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>

sound/pci/mixart/mixart_mixer.c

@@ -448,7 +448,7 @@ static int mixart_audio_sw_put(struct snd_kcontrol *kcontrol, struct snd_ctl_ele
 	return changed;
 }
 
-static struct snd_kcontrol_new mixart_control_output_switch = {
+static const struct snd_kcontrol_new mixart_control_output_switch = {
 	.iface =	SNDRV_CTL_ELEM_IFACE_MIXER,
 	.name =         "Master Playback Switch",
 	.info =         mixart_sw_info,		/* shared */
@@ -1024,7 +1024,7 @@ static int mixart_monitor_vol_put(struct snd_kcontrol *kcontrol, struct snd_ctl_
 	return changed;
 }
 
-static struct snd_kcontrol_new mixart_control_monitor_vol = {
+static const struct snd_kcontrol_new mixart_control_monitor_vol = {
 	.iface =	SNDRV_CTL_ELEM_IFACE_MIXER,
 	.access = (SNDRV_CTL_ELEM_ACCESS_READWRITE |
 		   SNDRV_CTL_ELEM_ACCESS_TLV_READ),
@@ -1091,7 +1091,7 @@ static int mixart_monitor_sw_put(struct snd_kcontrol *kcontrol, struct snd_ctl_e
 	return (changed != 0);
 }
 
-static struct snd_kcontrol_new mixart_control_monitor_sw = {
+static const struct snd_kcontrol_new mixart_control_monitor_sw = {
 	.iface =	SNDRV_CTL_ELEM_IFACE_MIXER,
 	.name =         "Monitoring Switch",
 	.info =         mixart_sw_info,		/* shared */