net/softnic: support QinQ PPPoE encapsulation
net/softnic: support QinQ PPPoE encapsulation

Add implementation of QinQ PPPoE packet encapsulation action.

Signed-off-by: Nemanja Marjanovic <49b67968d34b40974a9ee8dec4162f6921cbad25@intel.com>
Acked-by: Cristian Dumitrescu <25468b8a3698eeb3c368247f8635924bb4a1ce2c@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk