Support for link redundancy for CoS configured on an L2TP

One can now configure multiple ports on the same IQ2 and IQ2E PICs to support link redundancy for CoS on L2TP tunnels configured on an Ethernet interface. Link redundancy is useful when the active port is unavailable due to events such as: Disconnection of a cable, Rebooting of a remote end system, Re-routing the traffic through a different port due to network conditions. Moreover, when the link redundancy is enabled, the traffic to the LAC devices is re-routed through another Ethernet interface configured on the same IQ2 or IQ2E PIC and the L2TP sessions are maintained.