virtio-iommu: depend on PCI

The virtio-iommu device attaches itself to a PCI bus, so it makes
no sense to include it unless PCI is supported---and in fact
compilation fails without this change.

Reported-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 file changed