drivers/rtc/rtc-at91sam9.c: use module_platform_driver() macro

This driver does seems to do only platform_driver_register in the init
function and platform_driver_unregister in the exit function,

so replace all this code including the module_init and module_exit with
module_platform_driver macro...
Signed-off-by: Devendra Naga <develkernel412222@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-at91sam9.c

@@ -473,18 +473,7 @@ static struct platform_driver at91_rtc_driver = {
 	},
 };
 
-static int __init at91_rtc_init(void)
-{
-	return platform_driver_register(&at91_rtc_driver);
-}
-module_init(at91_rtc_init);
-
-static void __exit at91_rtc_exit(void)
-{
-	platform_driver_unregister(&at91_rtc_driver);
-}
-module_exit(at91_rtc_exit);
-
+module_platform_driver(at91_rtc_driver);
 
 MODULE_AUTHOR("Michel Benoit");
 MODULE_DESCRIPTION("RTC driver for Atmel AT91SAM9x");