ALSA: rme9652: 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>

sound/pci/rme9652/rme9652.c

@@ -2228,9 +2228,9 @@ static struct snd_pcm_hardware snd_rme9652_capture_subinfo =
 	.fifo_size =		0,
 };
 
-static unsigned int period_sizes[] = { 64, 128, 256, 512, 1024, 2048, 4096, 8192 };
+static const unsigned int period_sizes[] = { 64, 128, 256, 512, 1024, 2048, 4096, 8192 };
 
-static struct snd_pcm_hw_constraint_list hw_constraints_period_sizes = {
+static const struct snd_pcm_hw_constraint_list hw_constraints_period_sizes = {
 	.count = ARRAY_SIZE(period_sizes),
 	.list = period_sizes,
 	.mask = 0