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/twl4030-madc.c b/drivers/mfd/twl4030-madc.c
index 834f824..456ecb5 100644
--- a/drivers/mfd/twl4030-madc.c
+++ b/drivers/mfd/twl4030-madc.c
@@ -807,19 +807,7 @@
 		   },
 };
 
-static int __init twl4030_madc_init(void)
-{
-	return platform_driver_register(&twl4030_madc_driver);
-}
-
-module_init(twl4030_madc_init);
-
-static void __exit twl4030_madc_exit(void)
-{
-	platform_driver_unregister(&twl4030_madc_driver);
-}
-
-module_exit(twl4030_madc_exit);
+module_platform_driver(twl4030_madc_driver);
 
 MODULE_DESCRIPTION("TWL4030 ADC driver");
 MODULE_LICENSE("GPL");