ASoC: zte: spdif: constify snd_soc_dai_ops structure

This structure is only stored in the ops field of a snd_soc_dai_driver
structure. That field is declared const, so snd_soc_dai_ops structures
that have this property can be declared as const also.
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/zte/zx-spdif.c

@@ -264,7 +264,7 @@ static void zx_spdif_shutdown(struct snd_pcm_substream *substream,
 	(SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S18_3LE \
 	| SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S24_LE)
 
-static struct snd_soc_dai_ops zx_spdif_dai_ops = {
+static const struct snd_soc_dai_ops zx_spdif_dai_ops = {
 	.trigger	= zx_spdif_trigger,
 	.startup	= zx_spdif_startup,
 	.shutdown	= zx_spdif_shutdown,