ALSA: mips: constify snd_pcm_ops structures

snd_pcm_ops are not supposed to change at runtime. All functions
working with snd_pcm_ops provided by <sound/pcm.h> work with
const snd_pcm_ops. So mark the non-const structs as const.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/mips/sgio2audio.c

diff --git a/sound/mips/sgio2audio.c b/sound/mips/sgio2audio.c
index 603892f..71c9421 100644
--- a/sound/mips/sgio2audio.c
+++ b/sound/mips/sgio2audio.c
@@ -675,7 +675,7 @@ snd_sgio2audio_pcm_pointer(struct snd_pcm_substream *substream)
 }
 
 /* operators */
-static struct snd_pcm_ops snd_sgio2audio_playback1_ops = {
+static const struct snd_pcm_ops snd_sgio2audio_playback1_ops = {
 	.open =        snd_sgio2audio_playback1_open,
 	.close =       snd_sgio2audio_pcm_close,
 	.ioctl =       snd_pcm_lib_ioctl,
@@ -688,7 +688,7 @@ static struct snd_pcm_ops snd_sgio2audio_playback1_ops = {
 	.mmap =        snd_pcm_lib_mmap_vmalloc,
 };
 
-static struct snd_pcm_ops snd_sgio2audio_playback2_ops = {
+static const struct snd_pcm_ops snd_sgio2audio_playback2_ops = {
 	.open =        snd_sgio2audio_playback2_open,
 	.close =       snd_sgio2audio_pcm_close,
 	.ioctl =       snd_pcm_lib_ioctl,
@@ -701,7 +701,7 @@ static struct snd_pcm_ops snd_sgio2audio_playback2_ops = {
 	.mmap =        snd_pcm_lib_mmap_vmalloc,
 };
 
-static struct snd_pcm_ops snd_sgio2audio_capture_ops = {
+static const struct snd_pcm_ops snd_sgio2audio_capture_ops = {
 	.open =        snd_sgio2audio_capture_open,
 	.close =       snd_sgio2audio_pcm_close,
 	.ioctl =       snd_pcm_lib_ioctl,