of/platform: remove all of_bus_type and of_platform_bus_type references

Both of_bus_type and of_platform_bus_type are just #define aliases
for the platform bus.  This patch removes all references to them and
switches to the of_register_platform_driver()/of_unregister_platform_driver()
API for registering.

Subsequent patches will convert each user of of_register_platform_driver()
into plain platform_drivers without the of_platform_driver shim.  At which
point the of_register_platform_driver()/of_unregister_platform_driver()
functions can be removed.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/niu.c b/drivers/net/niu.c
index f6ecf61..8cb2b30 100644
--- a/drivers/net/niu.c
+++ b/drivers/net/niu.c
@@ -10251,14 +10251,14 @@
 	niu_debug = netif_msg_init(debug, NIU_MSG_DEFAULT);
 
 #ifdef CONFIG_SPARC64
-	err = of_register_driver(&niu_of_driver, &of_bus_type);
+	err = of_register_platform_driver(&niu_of_driver);
 #endif
 
 	if (!err) {
 		err = pci_register_driver(&niu_pci_driver);
 #ifdef CONFIG_SPARC64
 		if (err)
-			of_unregister_driver(&niu_of_driver);
+			of_unregister_platform_driver(&niu_of_driver);
 #endif
 	}
 
@@ -10269,7 +10269,7 @@
 {
 	pci_unregister_driver(&niu_pci_driver);
 #ifdef CONFIG_SPARC64
-	of_unregister_driver(&niu_of_driver);
+	of_unregister_platform_driver(&niu_of_driver);
 #endif
 }