add SPM_REFSPEC parameter to the tf-ci-gateway job

add SPM_REFSPEC parameter to the tf-ci-gateway job to
allow testing a specific refspec from the Hafnium project.

Signed-off-by: Zelalem Aweke <zelalem.aweke@arm.com>
Change-Id: I3e7f9650dc18033fa75b6f28b3c29d036eec68d1
diff --git a/tf-ci-gateway.yaml b/tf-ci-gateway.yaml
index a6284b4..574f634 100644
--- a/tf-ci-gateway.yaml
+++ b/tf-ci-gateway.yaml
@@ -48,6 +48,11 @@
         description: |
           tf-a-tests refspec to use. The master branch is used by default.
     - string:
+       name: SPM_REFSPEC
+       default: '+refs/heads/master:refs/remotes/origin/master'
+       description: |
+         SPM(Hafnium) refspec to use. The master branch is used by default.
+    - string:
         name: CI_REFSPEC
         default: '+refs/heads/master:refs/remotes/origin/master'
         description: |