regulator: stw481x-vmmc: Constify static structs

The only usage of stw481x_vmmc_ops is to assign its address to the ops
field in the regulator_desc struct which is a const pointer.

The only usage of vmmc_regulator is to pass its address to
of_get_regulator_init_data() and devm_regulator_register(), both which
take const pointers.

Make both of them const to allow the compiler to put them in read-only
memory.

Signed-off-by: Rikard Falkeborn <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/stw481x-vmmc.c

···
 	3300000,
 };
 
-static struct regulator_ops stw481x_vmmc_ops = {
+static const struct regulator_ops stw481x_vmmc_ops = {
 	.list_voltage = regulator_list_voltage_table,
 	.enable      = regulator_enable_regmap,
 	.disable     = regulator_disable_regmap,
···
 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
 };
 
-static struct regulator_desc vmmc_regulator = {
+static const struct regulator_desc vmmc_regulator = {
 	.name = "VMMC",
 	.id   = 0,
 	.ops  = &stw481x_vmmc_ops,