regulator: fixed: Constify static regulator_ops

The only usage of fixed_voltage_ops and fixed_voltage_clkenabled_ops is
to assign their address the ops field in the regulator_desc struct,
which is a const pointer. Make them const to allow the compiler to put
them in read-only memory.
make them const to allow the compiler to put them in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20200913084114.8851-3-rikard.falkeborn@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/fixed.c

@@ -123,10 +123,10 @@ of_get_fixed_voltage_config(struct device *dev,
 	return config;
 }
 
-static struct regulator_ops fixed_voltage_ops = {
+static const struct regulator_ops fixed_voltage_ops = {
 };
 
-static struct regulator_ops fixed_voltage_clkenabled_ops = {
+static const struct regulator_ops fixed_voltage_clkenabled_ops = {
 	.enable = reg_clock_enable,
 	.disable = reg_clock_disable,
 	.is_enabled = reg_clock_is_enabled,