dt-bindings: soc: mediatek: pwrap: add compatible for mt8188

Add dt-binding documentation of pwrap for Mediatek MT8188

Signed-off-by: Sen Chu <sen.chu@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/20220726104242.24839-1-sen.chu@mediatek.com


Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>