Add no-op cinder-tgt element
Add no-op cinder-tgt element

This will be required so tripleo-incubator change
I1e33af0cb78fa9477bc5a0b9b89b06b907b81fae can merge without
breaking CI.  This will need to merge, then the tripleo-incubator
change can merge, then the cinder refactor can merge.

Change-Id: I59091b047a70c1cf033733f4d1beaf6858574f94

radez/tripleo-image-elements,rdo-management/tripleo-image-elements,radez/tripleo-image-elements,openstack/tripleo-image-elements,rdo-management/tripleo-image-elements,openstack/tripleo-image-elements