pci_register_io_range() has only one definition, so there is no need for
the __weak attribute.  Remove it.
Tested-by: Ndann frazier <dann.frazier@canonical.com>
Signed-off-by: NGabriele Paoloni <gabriele.paoloni@huawei.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>