net/mlx5: DR, Add check for multi destination FTE

The driver should not allow rule that forward to more than one FT in TX
flow unless there is a specific support from the FW.

Signed-off-by: Erez Shitrit <erezsh@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>