net/mlx5e: Add TC offload support for the VF representors netdevice

The VF representors support only TC filter/action offloads
(not mqprio) and this is enabled for them by default.

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>