regulator: core: Use map_voltage_linear_range by default for list_voltage_linear_range

Use map_voltage_linear_range() if list_voltage_linear_range() is in use and
nothing is set.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index ba28d29..4766611 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2322,6 +2322,10 @@
 			    regulator_list_voltage_linear)
 				ret = regulator_map_voltage_linear(rdev,
 								min_uV, max_uV);
+			else if (rdev->desc->ops->list_voltage ==
+				 regulator_list_voltage_linear_range)
+				ret = regulator_map_voltage_linear_range(rdev,
+								min_uV, max_uV);
 			else
 				ret = regulator_map_voltage_iterate(rdev,
 								min_uV, max_uV);