dt-bindings: power: Add r8a779h0 SYSC power domain definitions

Add power domain indices for the Renesas R-Car V4M (R8A779H0) SoC.

Signed-off-by: Duy Nguyen <duy.nguyen.rh@renesas.com>
Signed-off-by: Hai Pham <hai.pham.ud@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/c5cbef71178cada761e9da7bcbb6f21334f93ef8.1706194617.git.geert+renesas@glider.be
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>