net: microchip: sparx5: Egress VLAN TPID configuration follows IFH

This changes the TPID of the egress frames to use the TPID stored in the
IFH (internal frame header), which ensures that this is the TPID classified
for the frame at ingress.

Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>