AETHER-45 Add support of latest features in BESS based SPGWU

This patchset resolves the issues below.
Also enable PFCP by default.
- AETHER-370 Add support of UP4 pipeline
- AETHER-371 Add support of PFCP iface
- AETHER-373 Make upf.json fully configurable

Change-Id: I665168156968c090f3c297228b7b35f3dc0d8ace
diff --git a/omec/omec-user-plane/templates/bin/_bessd-poststart.sh.tpl b/omec/omec-user-plane/templates/bin/_bessd-poststart.sh.tpl
index d073f81..b9e20fd 100644
--- a/omec/omec-user-plane/templates/bin/_bessd-poststart.sh.tpl
+++ b/omec/omec-user-plane/templates/bin/_bessd-poststart.sh.tpl
@@ -6,6 +6,6 @@
 
 set -ex
 
-until bessctl run /opt/bess/bessctl/conf/spgwu; do
+until bessctl run /opt/bess/bessctl/conf/up4; do
     sleep 2;
 done;