xen/pt: Mark TYPE_XEN_PT_DEVICE as hybrid

xen-pt doesn't set the is_express field, but is supposed to be
able to handle PCI Express devices too.  Mark it as hybrid.

Suggested-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/xen/xen_pt.c

@@ -966,6 +966,7 @@ static const TypeInfo xen_pci_passthrough_info = {
     .class_init = xen_pci_passthrough_class_init,
     .interfaces = (InterfaceInfo[]) {
         { INTERFACE_CONVENTIONAL_PCI_DEVICE },
+        { INTERFACE_PCIE_DEVICE },
         { },
     },
 };