In addition to the current multicast route actions, which include trap
route action and a forward route action, add the trap-and-forward multicast
route action, and implement it in the multicast routing hardware logic.

To implement that, add a trap-and-forward ACL action as the last action in
the route flexible action set. The used trap is the ACL2 trap, which marks
the packets with offload_mr_forward_mark, to prevent the packet from being
forwarded again by the kernel.

Note: At that stage the offloading logic does not support trap-and-forward
multicast routes. This patch adds the support only in the hardware logic.
Signed-off-by: Yotam Gigi <yotamg@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>