mfd: Convert MFD drivers to use module_platform_driver

Factors out some boilerplate code for drivers doing the default thing
for platform driver registration. Drivers using platform_driver_probe
or an initcall other than module_init can't be converted.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/intel_msic.c b/drivers/mfd/intel_msic.c
index 97c2776..b76657e 100644
--- a/drivers/mfd/intel_msic.c
+++ b/drivers/mfd/intel_msic.c
@@ -485,17 +485,7 @@
 	},
 };
 
-static int __init intel_msic_init(void)
-{
-	return platform_driver_register(&intel_msic_driver);
-}
-module_init(intel_msic_init);
-
-static void __exit intel_msic_exit(void)
-{
-	platform_driver_unregister(&intel_msic_driver);
-}
-module_exit(intel_msic_exit);
+module_platform_driver(intel_msic_driver);
 
 MODULE_DESCRIPTION("Driver for Intel MSIC");
 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");