PCI: Distribute available resources to hotplug-capable bridges

The same problem that we have with bus space applies to other resources
as well. Linux only allocates the minimal amount of resources so that
the devices currently present barely fit there. This prevents extending
the chain later on because the resource windows allocated for hotplug
downstream ports are too small.

Follow what we already did for bus number and assign all available extra
resources to hotplug-capable bridges. This makes it possible to extend the
hierarchy later.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>