ASoC: rx1950_uda1380: Constify rate constraints

The rate constraints in this board driver are not modified at runtime, so
make them const.

While we are at it also remove the unnecessary 0 initializer for the mask
field.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/samsung/rx1950_uda1380.c

@@ -38,16 +38,15 @@ static int rx1950_hw_params(struct snd_pcm_substream *substream,
 static int rx1950_spk_power(struct snd_soc_dapm_widget *w,
 				struct snd_kcontrol *kcontrol, int event);
 
-static unsigned int rates[] = {
+static const unsigned int rates[] = {
 	16000,
 	44100,
 	48000,
 };
 
-static struct snd_pcm_hw_constraint_list hw_rates = {
+static const struct snd_pcm_hw_constraint_list hw_rates = {
 	.count = ARRAY_SIZE(rates),
 	.list = rates,
-	.mask = 0,
 };
 
 static struct snd_soc_jack hp_jack;