If it is a vm nic, it can be adder to ovs-on-hyper-v by this way.
$vnic = Get-VMNetworkAdapter VM1
Connect-VMNetworkAdapter -VMNetworkAdapter $vnic -SwitchName external
$vnic | Set-VMNetworkAdapterOVSPort -OVSPortName ovs-port-1
ovs-vsctl.exe add-port br0 ovs-port-1
But if it is a physics nic, how do?