ASoC: Constify reg_default tables

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Peter Rosin <peda@axentia.se>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/codecs/max9768.c b/sound/soc/codecs/max9768.c
index e1c196a..e3ccea2 100644
--- a/sound/soc/codecs/max9768.c
+++ b/sound/soc/codecs/max9768.c
@@ -35,7 +35,7 @@
 	u32 flags;
 };
 
-static struct reg_default max9768_default_regs[] = {
+static const struct reg_default max9768_default_regs[] = {
 	{ 0, 0 },
 	{ 3,  MAX9768_CTRL_FILTERLESS},
 };