regulator: lock supply in regulator enable

This patch add locks around regulator supply enable.
Signed-off-by: Mattias Wallin <mattias.wallin@stericsson.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

drivers/regulator/core.c

@@ -1267,7 +1267,6 @@ static int _regulator_enable(struct regulator_dev *rdev)
 {
 	int ret, delay;
 
-	if (rdev->use_count == 0) {
 	/* do we need to enable the supply regulator first */
 	if (rdev->supply) {
 		mutex_lock(&rdev->supply->mutex);
@@ -1279,7 +1278,6 @@ static int _regulator_enable(struct regulator_dev *rdev)
 			return ret;
 		}
 	}
-	}
 
 	/* check voltage and requested load before enabling */
 	if (rdev->constraints &&