Add mitaka models with trusty

Mitaka models with trusty for maintenance team purposes.
Change-Id: I8eac7ac18d7f7632bdfb36c550eb1ee4c1b4cc80
diff --git a/classes/cluster/virtual-mcp-mitaka-dvr/openstack/gateway.yml b/classes/cluster/virtual-mcp-mitaka-dvr/openstack/gateway.yml
index d7d93e8..0717926 100644
--- a/classes/cluster/virtual-mcp-mitaka-dvr/openstack/gateway.yml
+++ b/classes/cluster/virtual-mcp-mitaka-dvr/openstack/gateway.yml
@@ -1,5 +1,5 @@
 classes:
-- system.linux.system.repo.mcp.openstack
+- system.linux.system.repo.mcp.apt_mirantis.openstack
 - system.linux.system.repo.mcp.extra
 - system.linux.system.repo.saltstack.xenial
 - system.linux.network.interface.single_ovs_dvr
@@ -13,7 +13,6 @@
     interface_mtu: 9000
     neutron_gateway_dvr: True
     neutron_gateway_agent_mode: dvr_snat
-    linux_system_codename: xenial
   neutron:
     gateway:
       notification: