i2c/busses: Use module_platform_driver()

Convert the drivers in drivers/i2c/busses/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Cc: Ben Dooks <ben-linux@fluff.org>
Acked-by: Jochen Friedrich <jochen@scram.de>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: Manuel Lauss <manuel.lauss@googlemail.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Yong Zhang <yong.zhang0@gmail.com>
Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/i2c/busses/i2c-ixp2000.c b/drivers/i2c/busses/i2c-ixp2000.c
index c01e951..5d263f90 100644
--- a/drivers/i2c/busses/i2c-ixp2000.c
+++ b/drivers/i2c/busses/i2c-ixp2000.c
@@ -148,18 +148,7 @@
 	},
 };
 
-static int __init ixp2000_i2c_init(void)
-{
-	return platform_driver_register(&ixp2000_i2c_driver);
-}
-
-static void __exit ixp2000_i2c_exit(void)
-{
-	platform_driver_unregister(&ixp2000_i2c_driver);
-}
-
-module_init(ixp2000_i2c_init);
-module_exit(ixp2000_i2c_exit);
+module_platform_driver(ixp2000_i2c_driver);
 
 MODULE_AUTHOR ("Deepak Saxena <dsaxena@plexity.net>");
 MODULE_DESCRIPTION("IXP2000 GPIO-based I2C bus driver");