drm: rcar-du: Fix comments to comply with the kernel coding style

To avoid mixing comment styles when new comments complying with the
kernel coding style are introduced, fix all multiline comments in one
go.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
8 files changed