regulator: core: Provide managed regulator registration

Many regulator drivers have a remove function that consists solely of
calling regulator_unregister() so provide a devm_regulator_register()
in order to allow this repeated code to be removed and help eliminate
error handling code.

Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 67e13aa..8474c7f 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -334,7 +334,12 @@
 struct regulator_dev *
 regulator_register(const struct regulator_desc *regulator_desc,
 		   const struct regulator_config *config);
+struct regulator_dev *
+devm_regulator_register(struct device *dev,
+			const struct regulator_desc *regulator_desc,
+			const struct regulator_config *config);
 void regulator_unregister(struct regulator_dev *rdev);
+void devm_regulator_unregister(struct device *dev, struct regulator_dev *rdev);
 
 int regulator_notifier_call_chain(struct regulator_dev *rdev,
 				  unsigned long event, void *data);