rocker: forward packets to CPU when port is joined to openvswitch

Teach rocker to forward packets to CPU when a port is joined to Open vSwitch.
There is scope to later refine what is passed up as per Open vSwitch flows
on a port.

This does not change the behaviour of rocker ports that are
not joined to Open vSwitch.

Signed-off-by: Simon Horman <simon.horman@netronome.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>