nfp: flower: tunnel neigh support bond offload

Support hardware offload when tunnel neigh out port is bond.
These feature work with the nfp firmware. If the firmware
supports the NFP_FL_FEATS_TUNNEL_NEIGH_LAG feature, nfp driver
write the bond information to the firmware neighbor table or
do nothing for bond. when neighbor MAC changes, nfp driver
need to update the neighbor information too.

Signed-off-by: Yanguo Li <yanguo.li@corigine.com>
Reviewed-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>