Use bridge resource definitions instead of using the PCI_BRIDGE_RESOURCES
constant with an integer offeset.

Link: https://lore.kernel.org/r/20200520183411.1534621-2-kw@linux.comSigned-off-by: NKrzysztof Wilczynski <kw@linux.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>