Add qgraph nodes for virtio-9p-pci and virtio-9p-device.
Both nodes produce virtio-9p, but virtio-9p-pci receives
a pci-bus and overrides virtio-pci QOSGraphObject and its functions,
while virtio-9p-device receives a virtio and implements
its own functions
Signed-off-by: Emanuele Giuseppe Esposito <e.emanuelegiuseppe@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
