update drm.h

   a) delta: only DRM_CAP_SYNCOBJ_TIMELINE
   b) Generated using make headers_install.
   c) Generated from origin/drm-misc-next commit 982c0500fd1a8012c31d3c9dd8de285129904656"

Signed-off-by: Chunming Zhou <david1.zhou@amd.com>
Suggested-by: Michel Dänzer <michel@daenzer.net>
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>