ASoC: intel: skl: 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: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/boards/skl_rt286.c

@@ -165,21 +165,21 @@ static int skylake_hdmi_init(struct snd_soc_pcm_runtime *rtd)
 	return 0;
 }
 
-static unsigned int rates[] = {
+static const unsigned int rates[] = {
 	48000,
 };
 
-static struct snd_pcm_hw_constraint_list constraints_rates = {
+static const struct snd_pcm_hw_constraint_list constraints_rates = {
 	.count = ARRAY_SIZE(rates),
 	.list  = rates,
 	.mask = 0,
 };
 
-static unsigned int channels[] = {
+static const unsigned int channels[] = {
 	2,
 };
 
-static struct snd_pcm_hw_constraint_list constraints_channels = {
+static const struct snd_pcm_hw_constraint_list constraints_channels = {
 	.count = ARRAY_SIZE(channels),
 	.list = channels,
 	.mask = 0,
@@ -264,11 +264,11 @@ static int skylake_dmic_fixup(struct snd_soc_pcm_runtime *rtd,
 	return 0;
 }
 
-static unsigned int channels_dmic[] = {
+static const unsigned int channels_dmic[] = {
 	2, 4,
 };
 
-static struct snd_pcm_hw_constraint_list constraints_dmic_channels = {
+static const struct snd_pcm_hw_constraint_list constraints_dmic_channels = {
 	.count = ARRAY_SIZE(channels_dmic),
 	.list = channels_dmic,
 	.mask = 0,