net/mlx4_core: Directly expose fields of HW flow steering rule control segment

Some of the fields for struct mlx4_net_trans_rule_hw_ctrl were packed into u32
and accessed through bit field operations. Expose and access them directly as
u8.

Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>