Instead of blindly claim support for hot-plugging of every
interface type out there we should copy approach we have for
device types: white listing supported types and explicitly error
out on unsupported ones.
For instance, trying to hotplug vhostuser interface results in
nothing usable from guest currently. vhostuser typed interfaces
require additional work on our side.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>