regulator: bcm590xx-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/bcm590xx-regulator.o
   text	   data	    bss	    dec	    hex	filename
   1807	   3360	      0	   5167	   142f regulator/bcm590xx-regulator.o

File size after: drivers/regulator/bcm590xx-regulator.o
   text	   data	    bss	    dec	    hex	filename
   2575	   2592	      0	   5167	   142f regulator/bcm590xx-regulator.o

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/bcm590xx-regulator.c

@@ -250,7 +250,7 @@ static int bcm590xx_get_enable_register(int id)
 	return reg;
 }
 
-static struct regulator_ops bcm590xx_ops_ldo = {
+static const struct regulator_ops bcm590xx_ops_ldo = {
 	.is_enabled		= regulator_is_enabled_regmap,
 	.enable			= regulator_enable_regmap,
 	.disable		= regulator_disable_regmap,
@@ -260,7 +260,7 @@ static struct regulator_ops bcm590xx_ops_ldo = {
 	.map_voltage		= regulator_map_voltage_iterate,
 };
 
-static struct regulator_ops bcm590xx_ops_dcdc = {
+static const struct regulator_ops bcm590xx_ops_dcdc = {
 	.is_enabled		= regulator_is_enabled_regmap,
 	.enable			= regulator_enable_regmap,
 	.disable		= regulator_disable_regmap,
@@ -270,7 +270,7 @@ static struct regulator_ops bcm590xx_ops_dcdc = {
 	.map_voltage		= regulator_map_voltage_linear_range,
 };
 
-static struct regulator_ops bcm590xx_ops_vbus = {
+static const struct regulator_ops bcm590xx_ops_vbus = {
 	.is_enabled		= regulator_is_enabled_regmap,
 	.enable			= regulator_enable_regmap,
 	.disable		= regulator_disable_regmap,