dpaa2-switch: mark skbs with offload_fwd_mark

If a switch port is under a bridge, the offload_fwd_mark should be setup
before sending the skb towards the stack so that the bridge does not try
to flood the packet on the other switch ports.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>