regulator: lp3971: Constify regulator_desc

Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

drivers/regulator/lp3971.c

@@ -309,7 +309,7 @@ static struct regulator_ops lp3971_dcdc_ops = {
 	.set_voltage = lp3971_dcdc_set_voltage,
 };
 
-static struct regulator_desc regulators[] = {
+static const struct regulator_desc regulators[] = {
 	{
 		.name = "LDO1",
 		.id = LP3971_LDO1,