drm/doc: rename FB_DAMAGE_CLIPS section

Make it more human-readable.
Signed-off-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Cc: Pekka Paalanen <ppaalanen@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201216202222.48146-2-contact@emersion.fr

Documentation/gpu/drm-kms.rst

@@ -475,8 +475,8 @@ Plane Composition Properties
 .. kernel-doc:: drivers/gpu/drm/drm_blend.c
    :export:
 
-FB_DAMAGE_CLIPS
-~~~~~~~~~~~~~~~
+Damage Tracking Properties
+--------------------------
 
 .. kernel-doc:: drivers/gpu/drm/drm_damage_helper.c
    :doc: overview