char: hw_random: convert drivers/char/hw_random/* to use module_platform_driver()

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

Cc: David S. Miller <davem@davemloft.net>
Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Alexander Clouter <alex@digriz.org.uk>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: David Daney <david.daney@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/char/hw_random/octeon-rng.c b/drivers/char/hw_random/octeon-rng.c
index 9cd0fec..0943edc 100644
--- a/drivers/char/hw_random/octeon-rng.c
+++ b/drivers/char/hw_random/octeon-rng.c
@@ -131,18 +131,7 @@
 	.remove		= __exit_p(octeon_rng_remove),
 };
 
-static int __init octeon_rng_mod_init(void)
-{
-	return platform_driver_register(&octeon_rng_driver);
-}
-
-static void __exit octeon_rng_mod_exit(void)
-{
-	platform_driver_unregister(&octeon_rng_driver);
-}
-
-module_init(octeon_rng_mod_init);
-module_exit(octeon_rng_mod_exit);
+module_platform_driver(octeon_rng_driver);
 
 MODULE_AUTHOR("David Daney");
 MODULE_LICENSE("GPL");