[doc] Update stable releases support status
[doc] Update stable releases support status

Train and Ussuri are moved to EM status which should be reflected in
our doc.

Change-Id: Ic4cee0eb776960deecaf5da752d5e0b7f9afcb5c

stackforge/os-ansible-deployment,openstack/openstack-ansible,openstack/openstack-ansible,stackforge/os-ansible-deployment