CI: Add repo dir to disk usage and ability to purge everything

Add the newly added repo dir to the disk usage calculation and add the
ability to remove each of the persistent directories.

Change-Id: Ib922ad42c62efdeccf01851ac751742ed67748ae
Signed-off-by: Jon Mason <jon.mason@arm.com>

.gitlab-ci.yml

@@ -108,7 +108,21 @@ usage:
   stage: prep
   when: manual
   script:
-  - du -h -s $DL_DIR $SSTATE_DIR
+  - du -h -s $DL_DIR $SSTATE_DIR $KAS_REPO_REF_DIR
+
+delete-dl-dir:
+  extends: .setup
+  stage: prep
+  when: manual
+  script:
+  - rm -rf $DL_DIR/*
+
+delete-repo-dir:
+  extends: .setup
+  stage: prep
+  when: manual
+  script:
+  - rm -rf $KAS_REPO_REF_DIR/*
 
 # Wipe out old sstate
 prune-sstate: