regulator: aat2870: Use regulator_map_voltage_ascend

The voltages in aat2870_ldo_voltages table are in ascendant order, so use
regulator_map_voltage_ascend.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/regulator/aat2870-regulator.c

@@ -99,6 +99,7 @@ static int aat2870_ldo_is_enabled(struct regulator_dev *rdev)
 
 static struct regulator_ops aat2870_ldo_ops = {
 	.list_voltage = regulator_list_voltage_table,
+	.map_voltage = regulator_map_voltage_ascend,
 	.set_voltage_sel = aat2870_ldo_set_voltage_sel,
 	.get_voltage_sel = aat2870_ldo_get_voltage_sel,
 	.enable = aat2870_ldo_enable,