dt-bindings: can: renesas,rcar-canfd: Document R-Car V4H support

Document support for the CAN-FD Interface on the Renesas R-Car V4H
(R8A779G0) SoC.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/all/d8158c78cc786c432df5a5e5bbad848b717aca71.1674499048.git.geert+renesas@glider.be


Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>