mtd: convert drivers/mtd/* to use module_spi_driver()

This patch converts the drivers in drivers/mtd/* 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: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c
index 236057e..5ec5fc9 100644
--- a/drivers/mtd/devices/mtd_dataflash.c
+++ b/drivers/mtd/devices/mtd_dataflash.c
@@ -946,18 +946,7 @@
 	/* FIXME:  investigate suspend and resume... */
 };
 
-static int __init dataflash_init(void)
-{
-	return spi_register_driver(&dataflash_driver);
-}
-module_init(dataflash_init);
-
-static void __exit dataflash_exit(void)
-{
-	spi_unregister_driver(&dataflash_driver);
-}
-module_exit(dataflash_exit);
-
+module_spi_driver(dataflash_driver);
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Andrew Victor, David Brownell");