ASoC: blackfin: 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/soc.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: Mark Brown <broonie@kernel.org>

sound/soc/blackfin/bf5xx-ac97-pcm.c

@@ -308,7 +308,7 @@ static	int bf5xx_pcm_copy_user(struct snd_pcm_substream *substream,
 }
 #endif
 
-static struct snd_pcm_ops bf5xx_pcm_ac97_ops = {
+static const struct snd_pcm_ops bf5xx_pcm_ac97_ops = {
 	.open		= bf5xx_pcm_open,
 	.ioctl		= snd_pcm_lib_ioctl,
 	.hw_params	= bf5xx_pcm_hw_params,

sound/soc/blackfin/bf5xx-i2s-pcm.c

@@ -318,7 +318,7 @@ static int bf5xx_pcm_silence(struct snd_pcm_substream *substream,
 	return 0;
 }
 
-static struct snd_pcm_ops bf5xx_pcm_i2s_ops = {
+static const struct snd_pcm_ops bf5xx_pcm_i2s_ops = {
 	.open		= bf5xx_pcm_open,
 	.ioctl		= snd_pcm_lib_ioctl,
 	.hw_params	= bf5xx_pcm_hw_params,