arm64: dts: mediatek: mt8188: Add support for SoC power domains

In preparation for adding support for hardware IP that requires
power switching, add the necessary power domains nodes for the
MT8188 SoC.

Link: https://lore.kernel.org/r/20240527093908.97574-5-angelogioacchino.delregno@collabora.com


Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>