arm64: dts: mediatek: cherry: Add platform regulators layout and config

arm64: dts: mediatek: cherry: Add platform regulators layout and config

Add the regulators layout for this platform, including the basic power
rails controlled by the EC (and/or always on).
Moreover, include the MT6359 PMIC devicetree and add some configuration
for its regulators, essential to keep the machine alive after booting.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20220704101321.44835-4-angelogioacchino.delregno@collabora.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>