Unhardcode baremetal-flat-network ip ranges

Allow to configure baremetal-flat-network cidr and
dhcp range via _param variables.
Add system model for neutron.gateway with ironic enabled.
Setup keystone admin_identity salt grains, used to create
openstack resources like neutron networks/subnets, ironic nodes.

Depends-On: I3f2db74e7e34310de19a44739828a874a5d5abac

Change-Id: I8bb529bf8b9ae2f115cbaa43beb16c819495d158
diff --git a/neutron/client/service/ironic.yml b/neutron/client/service/ironic.yml
index c400f96..3bc5be4 100644
--- a/neutron/client/service/ironic.yml
+++ b/neutron/client/service/ironic.yml
@@ -11,9 +11,12 @@
               shared: True
               admin_state_up: True
               provider_network_type: flat
-              provider_physical_network: physnet1
+              provider_physical_network: physnet3
               port_security_enabled: false
               subnet:
                 baremetal-subnet:
-                  cidr: 192.168.90.0/24
+                  cidr: ${_param:openstack_baremeta_neutron_subnet_cidr}
+                  allocation_pools:
+                    - start: ${_param:openstack_baremeta_neutron_subnet_allocation_start}
+                      end: ${_param:openstack_baremeta_neutron_subnet_allocation_end}
                   enable_dhcp: true