regulator: max77686: Make regulator_desc array const

The regulator_register() expects array of 'regulator_desc' to be const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/regulator/max77686.c b/drivers/regulator/max77686.c
index ef1af2d..0d103ba 100644
--- a/drivers/regulator/max77686.c
+++ b/drivers/regulator/max77686.c
@@ -350,7 +350,7 @@
 			<< MAX77686_OPMODE_BUCK234_SHIFT,		\
 }
 
-static struct regulator_desc regulators[] = {
+static const struct regulator_desc regulators[] = {
 	regulator_desc_ldo1_low(1),
 	regulator_desc_ldo_low(2),
 	regulator_desc_ldo(3),