hwmon: convert drivers/hwmon/* to use module_platform_driver()

This patch converts the drivers in drivers/hwmon/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Cc: Donggeun Kim <dg77.kim@samsung.com>
Cc: Simon Guinot <sguinot@lacie.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Ben Dooks <ben@simtec.co.uk>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: J Keerthy <j-keerthy@ti.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
diff --git a/drivers/hwmon/wm831x-hwmon.c b/drivers/hwmon/wm831x-hwmon.c
index 97b1f83..9b598ed 100644
--- a/drivers/hwmon/wm831x-hwmon.c
+++ b/drivers/hwmon/wm831x-hwmon.c
@@ -209,17 +209,7 @@
 	},
 };
 
-static int __init wm831x_hwmon_init(void)
-{
-	return platform_driver_register(&wm831x_hwmon_driver);
-}
-module_init(wm831x_hwmon_init);
-
-static void __exit wm831x_hwmon_exit(void)
-{
-	platform_driver_unregister(&wm831x_hwmon_driver);
-}
-module_exit(wm831x_hwmon_exit);
+module_platform_driver(wm831x_hwmon_driver);
 
 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 MODULE_DESCRIPTION("WM831x Hardware Monitoring");