Add packet traps for packets that are sampled / trapped by ACLs, so that
capable drivers could register them with devlink. Add documentation for
every added packet trap and packet trap group.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>