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/serial/sunhv.c b/drivers/serial/sunhv.c
index 36e2448..a779e22 100644
--- a/drivers/serial/sunhv.c
+++ b/drivers/serial/sunhv.c
@@ -644,12 +644,12 @@
 	if (tlb_type != hypervisor)
 		return -ENODEV;
 
-	return of_register_driver(&hv_driver, &of_bus_type);
+	return of_register_platform_driver(&hv_driver);
 }
 
 static void __exit sunhv_exit(void)
 {
-	of_unregister_driver(&hv_driver);
+	of_unregister_platform_driver(&hv_driver);
 }
 
 module_init(sunhv_init);