net/mlx5: Lag, Check shared fdb before creating MultiPort E-Switch

Currently, MultiPort E-Switch is requesting to create a LAG with shared
FDB without checking the LAG is supporting shared FDB.
Add the check.

Fixes: a32327a3 ("net/mlx5: Lag, Control MultiPort E-Switch single FDB mode")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Link: https://patch.msgid.link/1741644104-97767-5-git-send-email-tariqt@nvidia.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>