Improvement in fabric.p4 and bng.p4

- fabric.p4 now supports double tagged hosts
- bng.p4 now only manages PPPoE termination
- bng_ingress moved at the end of the fabric pipeline

Change-Id: Iff62238fde9ec6ddf7311312a98c041e3ab3aa8d
diff --git a/pipelines/fabric/src/main/resources/fabric.p4 b/pipelines/fabric/src/main/resources/fabric.p4
index fede305..86bd764 100644
--- a/pipelines/fabric/src/main/resources/fabric.p4
+++ b/pipelines/fabric/src/main/resources/fabric.p4
@@ -68,9 +68,6 @@
         spgw_ingress.apply(hdr.gtpu_ipv4, hdr.gtpu_udp, hdr.gtpu,
                            hdr.ipv4, hdr.udp, fabric_metadata, standard_metadata);
 #endif // WITH_SPGW
-#ifdef WITH_BNG
-        bng_ingress.apply(hdr, fabric_metadata, standard_metadata);
-#endif // WITH_BNG
         if (fabric_metadata.skip_forwarding == _FALSE) {
             forwarding.apply(hdr, fabric_metadata, standard_metadata);
         }
@@ -86,6 +83,10 @@
             process_set_source_sink.apply(hdr, fabric_metadata, standard_metadata);
 #endif
         }
+#ifdef WITH_BNG
+        bng_ingress.apply(hdr, fabric_metadata, standard_metadata);
+#endif // WITH_BNG
+
     }
 }