drm: rcar-du: Drop file name from comment header blocks

The comment blocks at the beginning of each file have a one-line
summary description of the file that includes the file name. While the
description is useful, the file name only creates opportunities for
mistakes (as seen in rcar_du_vsp.c) without any added value. Drop it.

Reported-by: Biju Das <biju.das.jz@bp.renesas.com>
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>