ASoC: mediatek: Constify hw_constraints

snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers.  Constify the corresponding static objects for better
hardening.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-By: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/mediatek/mt2701/mt2701-cs42448.c b/sound/soc/mediatek/mt2701/mt2701-cs42448.c
index aa5b31b..70f61d5 100644
--- a/sound/soc/mediatek/mt2701/mt2701-cs42448.c
+++ b/sound/soc/mediatek/mt2701/mt2701-cs42448.c
@@ -107,7 +107,7 @@
 
 static const unsigned int mt2701_cs42448_sampling_rates[] = {48000};
 
-static struct snd_pcm_hw_constraint_list mt2701_cs42448_constraints_rates = {
+static const struct snd_pcm_hw_constraint_list mt2701_cs42448_constraints_rates = {
 		.count = ARRAY_SIZE(mt2701_cs42448_sampling_rates),
 		.list = mt2701_cs42448_sampling_rates,
 		.mask = 0,