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>
diff --git a/sound/mips/hal2.c b/sound/mips/hal2.c
index 367d6c37..37d378a 100644
--- a/sound/mips/hal2.c
+++ b/sound/mips/hal2.c
@@ -711,7 +711,7 @@ static int hal2_capture_ack(struct snd_pcm_substream *substream)
 						 hal2_capture_transfer);
 }
 
-static struct snd_pcm_ops hal2_playback_ops = {
+static const struct snd_pcm_ops hal2_playback_ops = {
 	.open =        hal2_playback_open,
 	.close =       hal2_playback_close,
 	.ioctl =       snd_pcm_lib_ioctl,
@@ -723,7 +723,7 @@ static struct snd_pcm_ops hal2_playback_ops = {
 	.ack =         hal2_playback_ack,
 };
 
-static struct snd_pcm_ops hal2_capture_ops = {
+static const struct snd_pcm_ops hal2_capture_ops = {
 	.open =        hal2_capture_open,
 	.close =       hal2_capture_close,
 	.ioctl =       snd_pcm_lib_ioctl,