core: add IODeviceLatencyTargetSec
    
    This adds support for the following proposed latency based IO control
    mechanism.
    
      https://lkml.org/lkml/2018/6/5/428
    
    (cherry picked from commit 6ae4283cb14c4e4a895f4bbba703804e4128c86c)
    
    Resolves: #1831519
    
    patch_name: 0395-core-add-IODeviceLatencyTargetSec.patch
    present_in_specfile: true
    location_in_specfile: 395
    squash_commits: true