Input: convert I2C drivers to use module_i2c_driver()

This patch converts the drivers in drivers/input/* to use the
module_i2c_driver() macro which makes the code smaller and a bit
simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/keyboard/mcs_touchkey.c b/drivers/input/keyboard/mcs_touchkey.c
index af1aab3..64a0ca4 100644
--- a/drivers/input/keyboard/mcs_touchkey.c
+++ b/drivers/input/keyboard/mcs_touchkey.c
@@ -274,18 +274,7 @@
 	.id_table	= mcs_touchkey_id,
 };
 
-static int __init mcs_touchkey_init(void)
-{
-	return i2c_add_driver(&mcs_touchkey_driver);
-}
-
-static void __exit mcs_touchkey_exit(void)
-{
-	i2c_del_driver(&mcs_touchkey_driver);
-}
-
-module_init(mcs_touchkey_init);
-module_exit(mcs_touchkey_exit);
+module_i2c_driver(mcs_touchkey_driver);
 
 /* Module information */
 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");