ALSA: trident: 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/pci/trident/trident_main.c

@@ -2093,7 +2093,7 @@ static const struct snd_pcm_ops snd_trident_nx_playback_ops = {
 	.page =		snd_pcm_sgbuf_ops_page,
 };
 
-static struct snd_pcm_ops snd_trident_capture_ops = {
+static const struct snd_pcm_ops snd_trident_capture_ops = {
 	.open =		snd_trident_capture_open,
 	.close =	snd_trident_capture_close,
 	.ioctl =	snd_trident_ioctl,
@@ -2104,7 +2104,7 @@ static struct snd_pcm_ops snd_trident_capture_ops = {
 	.pointer =	snd_trident_capture_pointer,
 };
 
-static struct snd_pcm_ops snd_trident_si7018_capture_ops = {
+static const struct snd_pcm_ops snd_trident_si7018_capture_ops = {
 	.open =		snd_trident_capture_open,
 	.close =	snd_trident_capture_close,
 	.ioctl =	snd_trident_ioctl,