net: ethernet: ti: add NETIF_F_HW_TC hw feature flag for taprio offload

Currently drive supports taprio offload which is a tc feature offloaded
to cpsw hardware. So driver has to set the hw feature flag, NETIF_F_HW_TC
in the net device to be compliant. This patch adds the flag.

Fixes: 8127224c

 ("ethernet: ti: am65-cpsw-qos: add TAPRIO offload support")
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>