regulator: tps6507x: Use regulator_map_voltage_ascend

All regulators have ascendant voltage list in this driver.
Use regulator_map_voltage_ascend for them.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/regulator/tps6507x-regulator.c

@@ -356,6 +356,7 @@ static struct regulator_ops tps6507x_pmic_ops = {
 	.get_voltage_sel = tps6507x_pmic_get_voltage_sel,
 	.set_voltage_sel = tps6507x_pmic_set_voltage_sel,
 	.list_voltage = regulator_list_voltage_table,
+	.map_voltage = regulator_map_voltage_ascend,
 };
 
 #ifdef CONFIG_OF