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/mpr121_touchkey.c b/drivers/input/keyboard/mpr121_touchkey.c
index 1c1615d..caa218a 100644
--- a/drivers/input/keyboard/mpr121_touchkey.c
+++ b/drivers/input/keyboard/mpr121_touchkey.c
@@ -330,17 +330,7 @@
 	.remove		= __devexit_p(mpr_touchkey_remove),
 };
 
-static int __init mpr_touchkey_init(void)
-{
-	return i2c_add_driver(&mpr_touchkey_driver);
-}
-module_init(mpr_touchkey_init);
-
-static void __exit mpr_touchkey_exit(void)
-{
-	i2c_del_driver(&mpr_touchkey_driver);
-}
-module_exit(mpr_touchkey_exit);
+module_i2c_driver(mpr_touchkey_driver);
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");