use 'main' branch of RMM by default in all Job configs

Use 'main' branch of RMM by default during cloning in all job configs.

Change-Id: If92cf2026c9784dd4b677c556d5a8726a38ae3a0
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
diff --git a/tf-a-tftf-gerrit-tforg-l2.yaml b/tf-a-tftf-gerrit-tforg-l2.yaml
index a67e656..79d2af5 100644
--- a/tf-a-tftf-gerrit-tforg-l2.yaml
+++ b/tf-a-tftf-gerrit-tforg-l2.yaml
@@ -48,6 +48,11 @@
            description: |
              SPM (Hafnium) refspec to use.
         - string:
+           name: RMM_REFSPEC
+           default: '+refs/heads/main:refs/remotes/origin/main'
+           description: |
+             tf-rmm refspec to use. The main branch is used by default.
+        - string:
             name: CI_REFSPEC
             default: '+refs/heads/master:refs/remotes/origin/master'
         - string: