net/mlx5: DR, Create multi-destination flow table with level less than 64

Flow table that contains flow pointing to multiple flow tables or multiple
TIRs must have a level lower than 64. In our case it applies to muli-
destination flow table.
Fix the level of the created table to comply with HW Spec definitions, and
still make sure that its level lower than SW-owned tables, so that it
would be possible to point from the multi-destination FW table to SW
tables.

Fixes: 34583bee

 ("net/mlx5: DR, Create multi-destination table for SW-steering use")
Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Reviewed-by: Alex Vesker <valex@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>