virtio-iommu needs to be an integrated device, and our address
assignment code will make sure that is the case. If the user has
provided an explicit address, however, we should make sure any
addresses pointing to a different bus are rejected.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>