ALSA: pci: Constify snd_kcontrol_new items

Most of snd_kcontrol_new definitions are read-only and passed as-is.
Let's declare them as const for further optimization.

There should be no functional changes by this patch.

Link: https://lore.kernel.org/r/20200103081714.9560-38-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/cmipci.c b/sound/pci/cmipci.c
index ff55257..7f91742e 100644
--- a/sound/pci/cmipci.c
+++ b/sound/pci/cmipci.c
@@ -2256,7 +2256,7 @@ static int snd_cmipci_put_native_mixer_sensitive(struct snd_kcontrol *kcontrol,
 }
 
 
-static struct snd_kcontrol_new snd_cmipci_mixers[] = {
+static const struct snd_kcontrol_new snd_cmipci_mixers[] = {
 	CMIPCI_SB_VOL_STEREO("Master Playback Volume", SB_DSP4_MASTER_DEV, 3, 31),
 	CMIPCI_MIXER_SW_MONO("3D Control - Switch", CM_REG_MIXER1, CM_X3DEN_SHIFT, 0),
 	CMIPCI_SB_VOL_STEREO("PCM Playback Volume", SB_DSP4_PCM_DEV, 3, 31),
@@ -2567,7 +2567,7 @@ static int snd_cmipci_mic_in_mode_put(struct snd_kcontrol *kcontrol,
 }
 
 /* both for CM8338/8738 */
-static struct snd_kcontrol_new snd_cmipci_mixer_switches[] = {
+static const struct snd_kcontrol_new snd_cmipci_mixer_switches[] = {
 	DEFINE_MIXER_SWITCH("Four Channel Mode", fourch),
 	{
 		.name = "Line-In Mode",
@@ -2579,11 +2579,11 @@ static struct snd_kcontrol_new snd_cmipci_mixer_switches[] = {
 };
 
 /* for non-multichannel chips */
-static struct snd_kcontrol_new snd_cmipci_nomulti_switch =
+static const struct snd_kcontrol_new snd_cmipci_nomulti_switch =
 DEFINE_MIXER_SWITCH("Exchange DAC", exchange_dac);
 
 /* only for CM8738 */
-static struct snd_kcontrol_new snd_cmipci_8738_mixer_switches[] = {
+static const struct snd_kcontrol_new snd_cmipci_8738_mixer_switches[] = {
 #if 0 /* controlled in pcm device */
 	DEFINE_MIXER_SWITCH("IEC958 In Record", spdif_in),
 	DEFINE_MIXER_SWITCH("IEC958 Out", spdif_out),
@@ -2605,14 +2605,14 @@ static struct snd_kcontrol_new snd_cmipci_8738_mixer_switches[] = {
 };
 
 /* only for model 033/037 */
-static struct snd_kcontrol_new snd_cmipci_old_mixer_switches[] = {
+static const struct snd_kcontrol_new snd_cmipci_old_mixer_switches[] = {
 	DEFINE_MIXER_SWITCH("IEC958 Mix Analog", spdif_dac_out),
 	DEFINE_MIXER_SWITCH("IEC958 In Phase Inverse", spdi_phase),
 	DEFINE_MIXER_SWITCH("IEC958 In Select", spdif_in_sel1),
 };
 
 /* only for model 039 or later */
-static struct snd_kcontrol_new snd_cmipci_extra_mixer_switches[] = {
+static const struct snd_kcontrol_new snd_cmipci_extra_mixer_switches[] = {
 	DEFINE_MIXER_SWITCH("IEC958 In Select", spdif_in_sel2),
 	DEFINE_MIXER_SWITCH("IEC958 In Phase Inverse", spdi_phase2),
 	{
@@ -2625,14 +2625,14 @@ static struct snd_kcontrol_new snd_cmipci_extra_mixer_switches[] = {
 };
 
 /* card control switches */
-static struct snd_kcontrol_new snd_cmipci_modem_switch =
+static const struct snd_kcontrol_new snd_cmipci_modem_switch =
 DEFINE_CARD_SWITCH("Modem", modem);
 
 
 static int snd_cmipci_mixer_new(struct cmipci *cm, int pcm_spdif_device)
 {
 	struct snd_card *card;
-	struct snd_kcontrol_new *sw;
+	const struct snd_kcontrol_new *sw;
 	struct snd_kcontrol *kctl;
 	unsigned int idx;
 	int err;