regulator: fan53555: 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/fan53555.o
   text	   data	    bss	    dec	    hex	filename
   3512	    496	      8	   4016	    fb0	drivers/regulator/fan53555.o

File size after: drivers/regulator/fan53555.o
   text	   data	    bss	    dec	    hex	filename
   3768	    240	      8	   4016	    fb0	drivers/regulator/fan53555.o

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

drivers/regulator/fan53555.c

@@ -202,7 +202,7 @@ static int fan53555_set_ramp(struct regulator_dev *rdev, int ramp)
 				  CTL_SLEW_MASK, regval << CTL_SLEW_SHIFT);
 }
 
-static struct regulator_ops fan53555_regulator_ops = {
+static const struct regulator_ops fan53555_regulator_ops = {
 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
 	.set_voltage_time_sel = regulator_set_voltage_time_sel,