net/mlx5: Pass a namespace for packet reformat ID allocation

Currently we attach packet reformat actions only to the FDB namespace.
In preparation to be able to use that for NIC steering, pass the actual
namespace as a parameter.

Signed-off-by: Mark Bloch <markb@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>