dt-bindings: soc: renesas: Document R8A779G3 White Hawk Single

Document the compatible value for the Renesas R-Car V4H ES3.0
(R8A779G3) SoC, as used on the Renesas White Hawk Single board.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/1d2d2a6cbf31c817f574f6eed310a960e6175afe.1733156661.git.geert+renesas@glider.be