Fabric.p4 cherry-picks from onos-2.2

Publish fabric.p4 constants with fabric-api artifact

For consumption by third-party apps who wish to operate directly on
fabric.p4 tables and other entities.

(cherry picked from commit 8f6b5cdabf7828f6f7c017f288aad87c7bd0911a)

Backport fabric-tna dbuf support to v1model
(cherry picked from commit 4d1d67fa3abb4d7517e5836fbb82c899acffa951)

Update SPGW p4 namespace to match fabric-tna
(cherry picked from commit 35e4d196eb61104e7f96c62361a100bb454ee1cf)

Change-Id: I3230a508a601180060e1041d4369a54f519658e1
diff --git a/pipelines/fabric/impl/src/main/resources/fabric.p4 b/pipelines/fabric/impl/src/main/resources/fabric.p4
index 9f6b27d..ad3857d 100644
--- a/pipelines/fabric/impl/src/main/resources/fabric.p4
+++ b/pipelines/fabric/impl/src/main/resources/fabric.p4
@@ -56,14 +56,14 @@
     PortCountersControl() port_counters_control;
 #endif // WITH_PORT_COUNTER
 #ifdef WITH_SPGW
-    SpgwIngress() spgw_ingress;
+    SpgwIngress() spgw;
 #endif // WITH_SPGW
 
     apply {
         _PRE_INGRESS
         pkt_io_ingress.apply(hdr, fabric_metadata, standard_metadata);
 #ifdef WITH_SPGW
-        spgw_ingress.apply(hdr, fabric_metadata, standard_metadata);
+        spgw.apply(hdr, fabric_metadata, standard_metadata);
 #endif // WITH_SPGW
         filtering.apply(hdr, fabric_metadata, standard_metadata);
         if (fabric_metadata.skip_forwarding == _FALSE) {
@@ -95,7 +95,7 @@
     PacketIoEgress() pkt_io_egress;
     EgressNextControl() egress_next;
 #ifdef WITH_SPGW
-    SpgwEgress() spgw_egress;
+    SpgwEgress() spgw;
 #endif // WITH_SPGW
 
     apply {
@@ -103,7 +103,7 @@
         pkt_io_egress.apply(hdr, fabric_metadata, standard_metadata);
         egress_next.apply(hdr, fabric_metadata, standard_metadata);
 #ifdef WITH_SPGW
-        spgw_egress.apply(hdr, fabric_metadata);
+        spgw.apply(hdr, fabric_metadata);
 #endif // WITH_SPGW
 #ifdef WITH_BNG
         bng_egress.apply(hdr, fabric_metadata, standard_metadata);