We need a hook to release host bridge resources allocated when creating
root bus.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Use that device for pci_root_bus bridge pointer.

Use pci_release_bus_bridge_dev() to release allocated pci_host_bridge in
remove path.

Use root bus bridge pointer to get host bridge pointer instead of searching
host bridge list.  That leaves the host bridge list unused, so remove it.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

pci_host_bridge() looks like a C++ constructor.  Also separate
find_pci_root_bus() out.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Move host bridge-related code from probe.c to a new host-bridge.c.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>