nfp: flower: ignore offload of VF and PF repr MAC addresses

Currently MAC addresses of all repr netdevs, along with selected non-NFP
controlled netdevs, are offloaded to FW as potential tunnel end-points.
However, the addresses of VF and PF reprs are meaningless outside of
internal communication and it is only those of physical port reprs
required.

Modify the MAC address offload selection code to ignore VF/PF repr devs.

Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>