regulator: Use _regulator_get_voltage() consistently

Rather than referencing the get_voltage() operation directly in the
ops struct use the internal _regulator_get_voltage() API call to do
so, facilitating refactoring.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 5d07e5d..671eb53 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -581,14 +581,15 @@
 		return;
 
 	/* get output voltage */
-	output_uV = rdev->desc->ops->get_voltage(rdev);
+	output_uV = _regulator_get_voltage(rdev);
 	if (output_uV <= 0)
 		return;
 
 	/* get input voltage */
-	if (rdev->supply && rdev->supply->desc->ops->get_voltage)
-		input_uV = rdev->supply->desc->ops->get_voltage(rdev->supply);
-	else
+	input_uV = 0;
+	if (rdev->supply)
+		input_uV = _regulator_get_voltage(rdev);
+	if (input_uV <= 0)
 		input_uV = rdev->constraints->input_uV;
 	if (input_uV <= 0)
 		return;
@@ -1908,16 +1909,17 @@
 		goto out;
 
 	/* get output voltage */
-	output_uV = rdev->desc->ops->get_voltage(rdev);
+	output_uV = _regulator_get_voltage(rdev);
 	if (output_uV <= 0) {
 		rdev_err(rdev, "invalid output voltage found\n");
 		goto out;
 	}
 
 	/* get input voltage */
-	if (rdev->supply && rdev->supply->desc->ops->get_voltage)
-		input_uV = rdev->supply->desc->ops->get_voltage(rdev->supply);
-	else
+	input_uV = 0;
+	if (rdev->supply)
+		input_uV = _regulator_get_voltage(rdev->supply);
+	if (input_uV <= 0)
 		input_uV = rdev->constraints->input_uV;
 	if (input_uV <= 0) {
 		rdev_err(rdev, "invalid input voltage found\n");