ALSA: pcm: Make constraints lists const

They aren't modified by the core so the drivers can declare them const.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 8f312fa..7ae6719 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -1250,10 +1250,10 @@
 int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime,
 			       unsigned int cond,
 			       snd_pcm_hw_param_t var,
-			       struct snd_pcm_hw_constraint_list *l)
+			       const struct snd_pcm_hw_constraint_list *l)
 {
 	return snd_pcm_hw_rule_add(runtime, cond, var,
-				   snd_pcm_hw_rule_list, l,
+				   snd_pcm_hw_rule_list, (void *)l,
 				   var, -1);
 }