devices: add support for af-packet v2

Type: feature

Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>
Change-Id: I2ccaf1d512dcb72e414be8c69cbb538ebbe0e933
diff --git a/src/vnet/devices/af_packet/af_packet.api b/src/vnet/devices/af_packet/af_packet.api
index 4a5cfb0..a12da37 100644
--- a/src/vnet/devices/af_packet/af_packet.api
+++ b/src/vnet/devices/af_packet/af_packet.api
@@ -94,6 +94,7 @@
 enum af_packet_flags {
   AF_PACKET_API_FLAG_QDISC_BYPASS = 1, /* enable the qdisc bypass */
   AF_PACKET_API_FLAG_CKSUM_GSO = 2, /* enable checksum/gso */
+  AF_PACKET_API_FLAG_VERSION_2 = 8 [backwards_compatible], /* af packet v2, default is v3 */
 };
 
 /** \brief Create host-interface