regulator: max77620-regulator: constify regulator_ops structure

Declare regulator_ops structure as const as it is only stored in the ops
field of a regulator_desc structure. This field is of type const, so
regulator_ops structures having this property can be made const too.

File size before: drivers/regulator/max77620-regulator.o
text data bss dec hex filename
4811 6992 0 11803 2e1b regulator/max77620-regulator.o

File size after: drivers/regulator/max77620-regulator.o
text data bss dec hex filename
5075 6720 0 11795 2e13 regulator/max77620-regulator.o

Signed-off-by: Bhumika Goyal <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/max77620-regulator.c

···
 	return max77620_init_pmic(pmic, desc->id);
 }
 
-static struct regulator_ops max77620_regulator_ops = {
+static const struct regulator_ops max77620_regulator_ops = {
 	.is_enabled = max77620_regulator_is_enabled,
 	.enable = max77620_regulator_enable,
 	.disable = max77620_regulator_disable,