net/mlx5: DR, Use attributes struct for FW flow table creation

Instead of using multiple variables use a simple struct. The
number of passed argument was too high after adding the encap
decap support bits arguments used for multiple destination reformat.

Signed-off-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>