Simply move these inline functions outside the ifdef instead of duplicating
them as stubs in the !OF case. The struct device of_node field does not
depend on OF.
This also fixes the missing stubbed pci_bus_to_OF_node().
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>