power_supply: Convert drivers/power/* to use module_platform_driver()

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

Cc: Mike Rapoport <mike@compulab.co.il>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Nithish Mahalingam <nithish.mahalingam@intel.com>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Haojian Zhuang <haojian.zhuang@marvell.com>
Cc: Balaji Rao <balajirrao@openmoko.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Clifton Barnes <cabarnes@indesign-llc.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
diff --git a/drivers/power/ds2760_battery.c b/drivers/power/ds2760_battery.c
index cda03da..545874b 100644
--- a/drivers/power/ds2760_battery.c
+++ b/drivers/power/ds2760_battery.c
@@ -641,18 +641,7 @@
 	.resume	  = ds2760_battery_resume,
 };
 
-static int __init ds2760_battery_init(void)
-{
-	return platform_driver_register(&ds2760_battery_driver);
-}
-
-static void __exit ds2760_battery_exit(void)
-{
-	platform_driver_unregister(&ds2760_battery_driver);
-}
-
-module_init(ds2760_battery_init);
-module_exit(ds2760_battery_exit);
+module_platform_driver(ds2760_battery_driver);
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "