mailbox: mtk-cmdq: Add CMDQ driver support for mt8188

Add CMDQ driver support for mt8188 by adding its compatible and
driver data in CMDQ driver.

Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>