arm64: dts: mediatek: mt8173-elm: Drop regulator-compatible property

arm64: dts: mediatek: mt8173-elm: Drop regulator-compatible property

The "regulator-compatible" property has been deprecated since 2012 in
commit 13511def87b9 ("regulator: deprecate regulator-compatible DT
property"), which is so old it's not even mentioned in the converted
regulator bindings YAML file. It is also not listed in the MT6397
regulator bindings. Having them present produces a whole bunch of
validation errors:

    Unevaluated properties are not allowed ('regulator-compatible' was unexpected)

Drop the "regulator-compatible" property from the board dts. The
property values are the same as the node name, so everything should
continue to work.

Fixes: 689b937bedde ("arm64: dts: mediatek: add mt8173 elm and hana board")
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20241211052427.4178367-4-wenst@chromium.org
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>