As with IPv4, listen to NEIGH_UPDATE events from the ndisc table and
program relevant neighbours to the device's neighbour table.

Note that neighbours with a link-local IP address aren't programmed, as
packets with a link-local destination IP are trapped after LPM lookup
and never reach the neighbour table.
Signed-off-by: NArkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: NIdo Schimmel <idosch@mellanox.com>
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>