Pick default region from openstack_region for ironic

This patch makes sures ironic pick default region
from _param:openstack_region.

Change-Id: I35fd1db8d1af8a55d9275407aef153b4dba7f0d3
Related-Prod: PROD-25905
diff --git a/ironic/conductor/single.yml b/ironic/conductor/single.yml
index f2855cc..36d92be 100644
--- a/ironic/conductor/single.yml
+++ b/ironic/conductor/single.yml
@@ -35,3 +35,5 @@
           enabled: ${_param:ironic_memcache_security_enabled}
           strategy: ${_param:openstack_memcache_security_strategy}
           secret_key: ${_param:ironic_memcache_secret_key}
+      identity:
+        region: ${_param:openstack_region}