regulator: Convert virtual and userspace regulator consumer drivers to use module_platform_driver()

This patch converts virtual and userspace regulator consumer drivers to use the
module_platform_driver() macro which makes the code smaller and a bit simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/regulator/virtual.c b/drivers/regulator/virtual.c
index 858c1f8..ee0b161 100644
--- a/drivers/regulator/virtual.c
+++ b/drivers/regulator/virtual.c
@@ -352,17 +352,7 @@
 	},
 };
 
-static int __init regulator_virtual_consumer_init(void)
-{
-	return platform_driver_register(&regulator_virtual_consumer_driver);
-}
-module_init(regulator_virtual_consumer_init);
-
-static void __exit regulator_virtual_consumer_exit(void)
-{
-	platform_driver_unregister(&regulator_virtual_consumer_driver);
-}
-module_exit(regulator_virtual_consumer_exit);
+module_platform_driver(regulator_virtual_consumer_driver);
 
 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 MODULE_DESCRIPTION("Virtual regulator consumer");