net/can: convert drivers/net/can/* to use module_platform_driver()

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

Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Bhupesh Sharma <bhupesh.sharma@st.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Kurt Van Dijck <kurt.van.dijck@eia.be>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c
index 044ea06..6ea905c 100644
--- a/drivers/net/can/at91_can.c
+++ b/drivers/net/can/at91_can.c
@@ -1383,18 +1383,7 @@
 	.id_table = at91_can_id_table,
 };
 
-static int __init at91_can_module_init(void)
-{
-	return platform_driver_register(&at91_can_driver);
-}
-
-static void __exit at91_can_module_exit(void)
-{
-	platform_driver_unregister(&at91_can_driver);
-}
-
-module_init(at91_can_module_init);
-module_exit(at91_can_module_exit);
+module_platform_driver(at91_can_driver);
 
 MODULE_AUTHOR("Marc Kleine-Budde <mkl@pengutronix.de>");
 MODULE_LICENSE("GPL v2");