Install kpartx for nova-kvm.
Install kpartx for nova-kvm.

Nova invokes kpartx directly to do file injection (ugh), so we need it
installed on the nova-kvm compute hosts.

Fixes bug: 1211170

Change-Id: I67f677f91df5f4340ceaa14efde1945e7d4218f6

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