ALSA: ICE1712/24 - Change the Multi Track Peak control (level meters) from MIXER to PCM type

* PLEASE NOTE - this change requires the corresponding update of
  envy24control for ice1712 - kind of an ABI change.
* The "Multi Track Peak" control is read-only level meters indicator.
* The control is VERY confusing to most users since it is currently displayed
  in regular mixers. E.g. alsamixer ignores its read-only status
  and allows changing the levels with keys which makes no sense.
Signed-off-by: NPavel Hofman <pavel.hofman@ivitera.com>
Acked-by: NJaroslav Kysela <perex@perex.cz>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/pci/ice1712/ice1712.c

@@ -2259,7 +2259,7 @@ static int snd_ice1712_pro_peak_get(struct snd_kcontrol *kcontrol,
 }
 
 static struct snd_kcontrol_new snd_ice1712_mixer_pro_peak __devinitdata = {
-	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.iface = SNDRV_CTL_ELEM_IFACE_PCM,
 	.name = "Multi Track Peak",
 	.access = SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
 	.info = snd_ice1712_pro_peak_info,

sound/pci/ice1712/ice1724.c

@@ -2110,7 +2110,7 @@ static int snd_vt1724_pro_peak_get(struct snd_kcontrol *kcontrol,
 }
 
 static struct snd_kcontrol_new snd_vt1724_mixer_pro_peak __devinitdata = {
-	.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+	.iface = SNDRV_CTL_ELEM_IFACE_PCM,
 	.name = "Multi Track Peak",
 	.access = SNDRV_CTL_ELEM_ACCESS_READ | SNDRV_CTL_ELEM_ACCESS_VOLATILE,
 	.info = snd_vt1724_pro_peak_info,