Fixed spgw.p4 decapping GTP packets not meant to be decapped

Also reduces the number of tables used for downlink processing.

Change-Id: I09a67cfac335b805d80e90cf5bb69fbab931e80b
diff --git a/pipelines/fabric/src/main/resources/include/header.p4 b/pipelines/fabric/src/main/resources/include/header.p4
index c1df60e..25ac400 100644
--- a/pipelines/fabric/src/main/resources/include/header.p4
+++ b/pipelines/fabric/src/main/resources/include/header.p4
@@ -132,7 +132,6 @@
 }
 
 struct spgw_meta_t {
-    _BOOL             do_spgw;
     direction_t       direction;
     bit<16>           ipv4_len;
     bit<32>           teid;
@@ -291,6 +290,8 @@
     ipv4_t gtpu_ipv4;
     udp_t gtpu_udp;
     gtpu_t gtpu;
+    ipv4_t inner_ipv4;
+    udp_t inner_udp;
 #endif // WITH_SPGW
     ipv4_t ipv4;
 #ifdef WITH_IPV6