Add the missing dnsmasq for ironic

refer to https://github.com/openstack/kolla-ansible/blob/master/ansible/roles/ironic/defaults/main.yml#L38

Change-Id: I847815b61e932d27d1fa010f14e85d3edc7a01d9

doc/source/reference/ironic-guide.rst

@@ -10,6 +10,7 @@ Currently Kolla can deploy the Ironic services:
 
 - ironic-api
 - ironic-conductor
+- ironic-dnsmasq
 - ironic-inspector
 
 As well as a required PXE service, deployed as ironic-pxe.