[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/i2c/other/pt2258.c

@@ -185,7 +185,7 @@ static int pt2258_switch_put(struct snd_kcontrol *kcontrol,
 	return -EIO;
 }
 
-static DECLARE_TLV_DB_SCALE(pt2258_db_scale, -7900, 100, 0);
+static const DECLARE_TLV_DB_SCALE(pt2258_db_scale, -7900, 100, 0);
 
 int snd_pt2258_build_controls(struct snd_pt2258 *pt)
 {