Global option for enforcing scope (ENFORCE_SCOPE)

This updates each devstack service library, to use it as the
default value for service-specific RBAC configuration.

Change-Id: I41061d042206c411ee3dd94ce91098e612af7ae7
diff --git a/functions-common b/functions-common
index b2cf9d9..603e7d8 100644
--- a/functions-common
+++ b/functions-common
@@ -1154,7 +1154,7 @@
 }
 
 function is_ironic_enforce_scope {
-    is_service_enabled ironic && [[ "$IRONIC_ENFORCE_SCOPE" == "True" ]] && return 0
+    is_service_enabled ironic && [[ "$IRONIC_ENFORCE_SCOPE" == "True" || "$ENFORCE_SCOPE" == "True" ]] && return 0
     return 1
 }