hw/acpi: remove from root bus 0 the crs resources used by other buses.

If multiple root buses are used, root bus 0 cannot use all the
pci holes ranges. Remove the IO/mem ranges used by the other
primary buses.

Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>