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/wm8996.c b/sound/soc/codecs/wm8996.c
index 3dd063f..66f32be 100644
--- a/sound/soc/codecs/wm8996.c
+++ b/sound/soc/codecs/wm8996.c
@@ -117,7 +117,7 @@
 WM8996_REGULATOR_EVENT(1)
 WM8996_REGULATOR_EVENT(2)
 
-static struct reg_default wm8996_reg[] = {
+static const struct reg_default wm8996_reg[] = {
 	{ WM8996_POWER_MANAGEMENT_1, 0x0 },
 	{ WM8996_POWER_MANAGEMENT_2, 0x0 },
 	{ WM8996_POWER_MANAGEMENT_3, 0x0 },