dt-bindings: mediatek: modify VDOSYS0 mutex device tree Documentations for MT8188

modify VDOSYS0 mutex device tree Documentations for MT8188.

Signed-off-by: Nathan Lu <nathan.lu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221206020046.11333-4-nathan.lu@mediatek.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
