For BF with old FW which doesn't expose the E-Switch Manager vport ID,
E-Switch Manager port matching works correctly only when BF is in
embedded CPU mode.
This patch adds the limitation description.
Fixes: a564038699f9 ("net/mlx5: support E-Switch manager egress traffic match")
Cc: stable@dpdk.org
Signed-off-by: Shun Hao <shunh@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>