mfd: Use module_pci_driver

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

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Andres Salomon <dilinger@queued.net>
Cc: Ira W. Snyder <iws@ovro.caltech.edu>
Cc: Florian Fainelli <florian@openwrt.org>
Cc: Denis Turischev <denis@compulab.co.il>
Cc: Harald Welte <HaraldWelte@viatech.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/vx855.c

@@ -131,17 +131,7 @@ static struct pci_driver vx855_pci_driver = {
 	.remove		= __devexit_p(vx855_remove),
 };
 
-static int vx855_init(void)
-{
-	return pci_register_driver(&vx855_pci_driver);
-}
-module_init(vx855_init);
-
-static void vx855_exit(void)
-{
-	pci_unregister_driver(&vx855_pci_driver);
-}
-module_exit(vx855_exit);
+module_pci_driver(vx855_pci_driver);
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");