net/mlx5: Lag, offload active-backup drops to hardware

In active-backup mode the backup interface's packets are dropped by the
bond device. In switchdev where TC rules are offloaded to the FDB
this can lead to packets being hit in the FDB where without offload
they would have been dropped before reaching TC rules in the kernel.

Create a drop rule to make sure packets on inactive ports are dropped
before reaching the FDB.

Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>