drm/doc/rfc: Mark drm_scheduler as completed

drm/doc/rfc: Mark drm_scheduler as completed

Current drm-xe-next doesn't have any drm/scheduler patch that is not
already accepted in drm-misc-next. This completed this goal with
the consensus of how the drm/scheduler fits to the fw scheduling and
the relationship between drm_gpu_scheduler and drm_sched_entity.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231201042158.80009-3-rodrigo.vivi@intel.com
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>