Input: convert SPI drivers to use module_spi_driver()

This patch converts the drivers in drivers/input/* to use the
module_spi_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/touchscreen/ad7879-spi.c b/drivers/input/touchscreen/ad7879-spi.c
index 9b2e1c2..db49abf 100644
--- a/drivers/input/touchscreen/ad7879-spi.c
+++ b/drivers/input/touchscreen/ad7879-spi.c
@@ -157,17 +157,7 @@
 	.remove		= __devexit_p(ad7879_spi_remove),
 };
 
-static int __init ad7879_spi_init(void)
-{
-	return spi_register_driver(&ad7879_spi_driver);
-}
-module_init(ad7879_spi_init);
-
-static void __exit ad7879_spi_exit(void)
-{
-	spi_unregister_driver(&ad7879_spi_driver);
-}
-module_exit(ad7879_spi_exit);
+module_spi_driver(ad7879_spi_driver);
 
 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 MODULE_DESCRIPTION("AD7879(-1) touchscreen SPI bus driver");