regulator: axp20x: Use regulator_map_voltage_ascend for LDO4
The voltages in axp20x_ldo4_data 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>
authored by