Add the host bridge bus number aperture to the resource list.
Like the MMIO and I/O port apertures, this is used when assigning
resources to hot-added devices or in the case of conflicts.
[bhelgaas: changelog] CC: Paul Mackerras <paulus@samba.org> CC: linuxppc-dev@lists.ozlabs.org CC: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>