regulator: Report actual configured voltage to set_voltage()

Change the interface used by set_voltage() to report the selected value
to the regulator core in terms of a selector used by list_voltage().
This allows the regulator core to know the voltage that was chosen
without having to do an explict get_voltage(), which would be much more
expensive as it will generally access hardware.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/drivers/regulator/ab8500.c b/drivers/regulator/ab8500.c
index db6b70f..2f4ec0f 100644
--- a/drivers/regulator/ab8500.c
+++ b/drivers/regulator/ab8500.c
@@ -215,7 +215,8 @@
 }
 
 static int ab8500_regulator_set_voltage(struct regulator_dev *rdev,
-		int min_uV, int max_uV)
+					int min_uV, int max_uV,
+					unsigned *selector)
 {
 	int regulator_id, ret;
 	struct ab8500_regulator_info *info = rdev_get_drvdata(rdev);
@@ -232,6 +233,8 @@
 		return ret;
 	}
 
+	*selector = ret;
+
 	/* set the registers for the request */
 	ret = abx500_mask_and_set_register_interruptible(info->dev,
 		info->voltage_bank, info->voltage_reg,