Add ui elements for CentOS to use kernel-ml

Adds new option to vlan splinters settings to enable Fedora main-line kernel
 currently 3.11

When chosen will send kernel_ml: 1 in ks-meta to cobbler

requires https://review.openstack.org/#/c/75243/

Change-Id: I77e3ba1f8875d38745fe972be2eb73bd6ad155bb
Related-bug: #1263072
Closes-bug: #1282493
Merge "Add ui elements for CentOS to use kernel-ml"