ci: Add the ability to run JJB from private branch/fork

Add the ability to run JJB from private branch/fork

jjb-deploy.yaml:
- Add GIT_REPO parameter (not required) with default value

jjb.sh:
- Changing PS4 for more indicative debug prompt
- Adding flags to get the repo and branch

jjb-deploy.yaml:
- Calling the jjb.sh with the correct flags

Signed-off-by: liranmauda <liran.mauda@gmail.com>

deploy/jjb-validate.yaml

@@ -25,7 +25,7 @@ objects:
               image: image-registry.openshift-image-registry.svc:5000/ceph-csi/jjb:latest
               env:
                 - name: GIT_REPO
-                  value: https://github.com/ceph/ceph-csi
+                  value: "${GIT_REPO}"
                 - name: GIT_REF
                   value: "${GIT_REF}"
           restartPolicy: Never
@@ -37,3 +37,7 @@ parameters:
     description: the git branch or other ref to checkout and validate
     value: ci/centos
     required: false
+  - name: GIT_REPO
+    description: the git repo or other fork to checkout and validate
+    value: https://github.com/ceph/ceph-csi
+    required: false