mlxsw: spectrum: Allow different traps to have different actions

Up until now we only trapped packets to CPU, but we are going to allow
some packets to be mirrored (trap & forward) to CPU.

Extend the Rx listener with 'action' member.

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