drm: Remove dev->kdriver

With the last patch to ditch the ->get_name callbacks the last
user is now gone.

Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --cc drivers/gpu/drm/drm_pci.c
Simple merge

diff --cc drivers/gpu/drm/drm_platform.c
Simple merge

diff --cc drivers/gpu/drm/drm_usb.c
Simple merge

diff --cc include/drm/drmP.h
Simple merge