drm/mediatek: dp: Add the audio divider to mtk_dp_data struct

Due to the difference of HW, different dividers need to be set.

Signed-off-by: Shuijing Li <shuijing.li@mediatek.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20230822024155.26670-4-shuijing.li@mediatek.com/


Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>