USO features of virtio-net device depend on kernel ability
to support them, for backward compatibility by default the
features are disabled on 8.0 and earlier.

Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
Signed-off-by: Andrew Melnychecnko <andrew@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>