net/mlx5e: Offload TC eswitch rules for VFs belonging to different PFs

When the merged eswitch capability is supported, allow offloading rules
between VFs which belong to different PFs (and hence have different
eswitch affinity).

Signed-off-by: Rabie Loulou <rabiel@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Shahar Klein <shahark@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>