arm64: dts: mediatek: mt8395-kontron-i1200: Fix MT6360 regulator nodes

arm64: dts: mediatek: mt8395-kontron-i1200: Fix MT6360 regulator nodes

All of the MT6360 regulator nodes were wrong and would not probe
because the regulator names are supposed to be lower case, but
they are upper case in this devicetree.

Change all nodes to be lower case to get working regulators.

Fixes: 94aaf79a6af5 ("arm64: dts: mediatek: add Kontron 3.5"-SBC-i1200")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Fei Shao <fshao@chromium.org>
Link: https://lore.kernel.org/r/20250724083914.61351-38-angelogioacchino.delregno@collabora.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>