ci-dockerfiles-deployment: Add params to allow to run manually

Have a params with suitable defaults, which are otherwise set by Gerrit
trigger.

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: I2262ea3085b81c187c2c432f6cb2dba5aa138a91
diff --git a/ci-dockerfiles-deployment.yaml b/ci-dockerfiles-deployment.yaml
index 44f3786..0ecf0ef 100644
--- a/ci-dockerfiles-deployment.yaml
+++ b/ci-dockerfiles-deployment.yaml
@@ -20,6 +20,20 @@
     node: build-amd64
     concurrent: false
     display-name: 'CI Dockerfiles build/publish deployment'
+    parameters:
+        - string:
+            name: GERRIT_PROJECT
+            default: 'ci/dockerfiles'
+            description: |
+              Git project to build (also set by Gerrit trigger)
+        - string:
+            name: GERRIT_BRANCH
+            default: 'master'
+            description: |
+              Git branch to build (also set by Gerrit trigger)
+        - string:
+            name: GERRIT_REFSPEC
+            default: ''
     scm:
         - git:
             url: https://review.trustedfirmware.org/${GERRIT_PROJECT}