When looking for slots suitable for a PCI device, libvirt
might need to add an extra PCI controller: for pSeries guests,
we want that extra controller to be a PHB (pci-root) rather
than a PCI bridge.
Signed-off-by: NAndrea Bolognani <abologna@redhat.com>
Reviewed-by: NLaine Stump <laine@laine.org>