ppc64le: add UNBUILDABLE_IMAGES entries
ppc64le: add UNBUILDABLE_IMAGES entries

Change-Id: I6b8f52a1f2227ecb74e3ae59ef1e67d5b5ce1886

rahulunair/kolla,stackforge/kolla,stackforge/kolla,stackforge/kolla,openstack/kolla,openstack/kolla,rahulunair/kolla