Build upf-epc image with haswell CPU option

Change-Id: I00dc7e9959de4275d93152d843ca49d0ca0a24a3
diff --git a/jjb/omec-ci.yaml b/jjb/omec-ci.yaml
index ed32c7f..002b00a 100644
--- a/jjb/omec-ci.yaml
+++ b/jjb/omec-ci.yaml
@@ -224,6 +224,7 @@
           build-timeout: 30
           docker-repo: 'omecproject'
           build-node: 'ubuntu16.04-basebuild-2c-4g'
+          extraEnvironmentVars: CPU=haswell
 
 # Combined pipeline
 - job-template: