rtc: convert rtc spi drivers to module_spi_driver

Factor out some boilerplate code for spi driver registration into
module_spi_driver.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Mark Jackson <mpfj@mimc.co.uk>
Cc: Dennis Aberilla <denzzzhome@yahoo.com>
Cc: Nikolaus Voss <n.voss@weinmann.de>
Cc: "Kim B. Heino" <Kim.Heino@bluegiga.com>
Cc: Raphael Assenat <raph@raphnet.net>
Cc: Chris Verges <chrisv@cyberswitching.com>
Cc: Magnus Damm <damm@opensource.se>
Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
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>
diff --git a/drivers/rtc/rtc-m41t93.c b/drivers/rtc/rtc-m41t93.c
index ef71132..10f1c29 100644
--- a/drivers/rtc/rtc-m41t93.c
+++ b/drivers/rtc/rtc-m41t93.c
@@ -206,17 +206,7 @@
 	.remove = __devexit_p(m41t93_remove),
 };
 
-static __init int m41t93_init(void)
-{
-	return spi_register_driver(&m41t93_driver);
-}
-module_init(m41t93_init);
-
-static __exit void m41t93_exit(void)
-{
-	spi_unregister_driver(&m41t93_driver);
-}
-module_exit(m41t93_exit);
+module_spi_driver(m41t93_driver);
 
 MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>");
 MODULE_DESCRIPTION("Driver for ST M41T93 SPI RTC");