net/mlx5: fs, allow flow table creation with a UID

Add UID field to flow table attributes to allow creating flow tables
with a non default (zero) uid.

Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Alex Vesker <valex@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>