Add missed suspend/resume callbacks to properly restore networking after
suspend/resume cycle.

Fixes: ed3525ed ("net: ethernet: ti: introduce cpsw switchdev based driver part 1 - dual-emac")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>