dt-bindings: soc: mediatek: add mt8188 svs dt-bindings

Add mt8188 svs compatible in dt-bindings.

Signed-off-by: Mark Tseng <chun-jen.tseng@mediatek.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230921052637.30444-2-chun-jen.tseng@mediatek.com