arm64: dts: mediatek: mt8183: Move thermal-zones to the root node

The thermal zones are not a soc bus device: move it to the root
node to solve simple_bus_reg warnings.

Cc: stable@vger.kernel.org
Fixes: b325ce39 ("arm64: dts: mt8183: add thermal zone node")
Link: https://lore.kernel.org/r/20231025093816.44327-9-angelogioacchino.delregno@collabora.com


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