PCI: show host bridges and root bus resources

Show the bus number and resources for every root bus we create.  This
will become more interesting when we supply the correct resources
instead of using the defaults (ioport_resource and iomem_resource).

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>