arm64: dts: renesas: r8a779a0: Add VSPD support

Provide VSPD support on the R-Car V3U SoC.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20210322172919.1154686-3-kieran.bingham+renesas@ideasonboard.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>