arm64: defconfig: Enable R8A779H0 SoC

Enable support for the Renesas R-Car V4M (R8A779H0) SoC in the ARM64
defconfig.

Signed-off-by: Linh Phung <linh.phung.jy@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/2e3b5ac22b92bd507940d1644bbff831a773721b.1706194617.git.geert+renesas@glider.be