regulator: tps65217: Use regulator_map_voltage_ascend for LDO1

The voltages in LDO1_VSEL_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>
diff --git a/drivers/regulator/tps65217-regulator.c b/drivers/regulator/tps65217-regulator.c
index 8482f6b..f7ed20a 100644
--- a/drivers/regulator/tps65217-regulator.c
+++ b/drivers/regulator/tps65217-regulator.c
@@ -134,6 +134,7 @@
 	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
 	.set_voltage_sel	= tps65217_pmic_set_voltage_sel,
 	.list_voltage		= regulator_list_voltage_table,
+	.map_voltage		= regulator_map_voltage_ascend,
 };
 
 static const struct regulator_desc regulators[] = {