[ALSA] Add even more 'const' to everything related to TLV

Mark TLV data as 'const'
Signed-of-by: Philipp Matthias Hahn <pmhahn@pmhahn.de>

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

sound/drivers/vx/vx_mixer.c

@@ -716,7 +716,7 @@ static int vx_monitor_sw_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_
 	return 0;
 }
 
-static DECLARE_TLV_DB_SCALE(db_scale_audio_gain, -10975, 25, 0);
+static const DECLARE_TLV_DB_SCALE(db_scale_audio_gain, -10975, 25, 0);
 
 static struct snd_kcontrol_new vx_control_audio_gain = {
 	.iface =	SNDRV_CTL_ELEM_IFACE_MIXER,