ALSA: core: Constify the name in new kcontrols

We never modify it and this lets us use a const string as the name without
warnings.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Liam Girdwood <lrg@ti.com>

include/sound/control.h

@@ -40,7 +40,7 @@ struct snd_kcontrol_new {
 	snd_ctl_elem_iface_t iface;	/* interface identifier */
 	unsigned int device;		/* device/client number */
 	unsigned int subdevice;		/* subdevice (substream) number */
-	unsigned char *name;		/* ASCII name of item */
+	const unsigned char *name;	/* ASCII name of item */
 	unsigned int index;		/* index of item */
 	unsigned int access;		/* access rights */
 	unsigned int count;		/* count of same elements */