regulator: dt-bindings: mt6358: Convert to DT schema

regulator: dt-bindings: mt6358: Convert to DT schema

Convert this from the old style text based binding to the new DT schema
style. This will make adding the MT6366 portion easier.

The examples have been trimmed down considerably, and the remaining
entries now match what is seen in actual device trees, minus some
properties that aren't covered by the bindings yet, or don't make
sense on their own.

The original submitter seems to have left MediaTek, so instead the
submitter and maintainer for the MT6366 binding is listed as the
maintainer here.

Cc: Zhiyong Tao <zhiyong.tao@mediatek.com>
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230928085537.3246669-3-wenst@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>