drm/todo: Remove i915 device_link task

Done with

commit aef9f33b


Author: Imre Deak <imre.deak@intel.com>
Date:   Tue Oct 23 17:43:10 2018 +0300

    drm/i915: Ensure proper HDA suspend/resume ordering with a device link

Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: Sean Paul <sean@poorly.run>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20191022152530.22038-1-daniel.vetter@ffwll.ch