Pick openstack_region for cinder services from param

Region is not passed in cinder metadata for the following classes:
  * cinder/control/single.yml
  * cinder/volume/local.yml
  * cinder/volume/single.yml

This patch makes sure _param:openstack_region is passed correctly.

Change-Id: I9b477a85965acaeb4e0c6319eeea63cc28f3556b
Related-Prod: PROD-21075
diff --git a/cinder/control/single.yml b/cinder/control/single.yml
index 66aea6d..d442693 100644
--- a/cinder/control/single.yml
+++ b/cinder/control/single.yml
@@ -19,4 +19,5 @@
         host: ${_param:single_address}
       identity:
         protocol: ${_param:internal_protocol}
+        region: ${_param:openstack_region}