staging: android: Avoid using camelcase in binder.h

This changes the following:

1: BinderDriverReturnProtocol -> binder_driver_return_protocol
2: BinderDriverCommandProtocol -> binder_driver_return_protocol

These enums are not currently used, but still generate noise in checkpatch.

Well, did. They don't now :)

Signed-off-by: Cruz Julian Bishop <cruzjbishop@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>