mlxsw: spectrum: Add FID miss trap

When there is no FID set for a specific packet, the HW will drop it.
However, by default these packets are useful to be delivered to CPU as
it can inspect them and program HW accordingly. So add this trap.

This would only ever happen when port is enslaved to an OVS master.
Otherwise, packets would be dropped during VLAN / STP filtering,
before FID classification.

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