mlxsw: spectrum_trap: Lookup and pass cookie down to devlink_trap_report()

Use the cookie index received along with the packet to lookup original
flow_offload cookie binary and pass it down to devlink_trap_report().
Add "fa_cookie" metadata to the ACL trap.

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