coreos-kernel: roll forward to 3.16 again, minus KASLR

Our Xen boot failure appears to be related to enabling KASLR and
helpuflly the 'nokaslr' command line option does not help. Disable the
feature entirely until the bugs are shaken out.
Merge pull request #836 from marineam/revert

coreos-kernel: roll forward to 3.16 again, minus KASLR