ARM: dts: renesas: Add R8A779G0 V4H DT extras

Add R8A779G0 V4H DT extras for U-Boot.

Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Signed-off-by: Hai Pham <hai.pham.ud@renesas.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
[Marek: Update compatible string to match latest upstream]