[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>
diff --git a/sound/pcmcia/vx/vxp_mixer.c b/sound/pcmcia/vx/vxp_mixer.c
index bced7b6..2b1f996 100644
--- a/sound/pcmcia/vx/vxp_mixer.c
+++ b/sound/pcmcia/vx/vxp_mixer.c
@@ -64,7 +64,7 @@
 	return 0;
 }
 
-static DECLARE_TLV_DB_SCALE(db_scale_mic, -21, 3, 0);
+static const DECLARE_TLV_DB_SCALE(db_scale_mic, -21, 3, 0);
 
 static struct snd_kcontrol_new vx_control_mic_level = {
 	.iface =	SNDRV_CTL_ELEM_IFACE_MIXER,