[ALSA] at73c213 - Use common callback

Use snd_ctl_boolean_mono_info callback to simplify.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
diff --git a/sound/spi/at73c213.c b/sound/spi/at73c213.c
index fee869b..bfe17b3 100644
--- a/sound/spi/at73c213.c
+++ b/sound/spi/at73c213.c
@@ -536,16 +536,7 @@
 	return retval;
 }
 
-static int snd_at73c213_mono_switch_info(struct snd_kcontrol *kcontrol,
-				  struct snd_ctl_elem_info *uinfo)
-{
-	uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
-	uinfo->count = 1;
-	uinfo->value.integer.min = 0;
-	uinfo->value.integer.max = 1;
-
-	return 0;
-}
+#define snd_at73c213_mono_switch_info	snd_ctl_boolean_mono_info
 
 static int snd_at73c213_mono_switch_get(struct snd_kcontrol *kcontrol,
 				 struct snd_ctl_elem_value *ucontrol)