arm64: dts: renesas: r8a774a1: Add CANFD support

Add CANFD support to the SoC specific dtsi.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>