DO-NOT-MERGE: Use migration branch for code-coverage job

Change-Id: I83b4376f5c2ff9f13c3abcce2936804d315789ae
Signed-off-by: Saheer Babu <saheer.babu@arm.com>
diff --git a/tf-m-code-coverage.yaml b/tf-m-code-coverage.yaml
index fd48e5e..a2b84c5 100644
--- a/tf-m-code-coverage.yaml
+++ b/tf-m-code-coverage.yaml
@@ -33,7 +33,7 @@
           default: 'https://git.trustedfirmware.org/ci/tf-m-ci-scripts'
       - string:
           name: 'CI_SCRIPTS_BRANCH'
-          default: 'master'
+          default: 'openci-migration'
           description: |
             Branch of CI_SCRIPTS_REPO to use; also accepts Gerrit patch refspec like 'refs/changes/98/29798/1'
       - string: