drm/mediatek: Add suffix 0 to DDP_COMPONENT_DITHER for mt8195 vdosys0

Because mt8195 vdosys0 has 2 DITHER components,
so the suffix 0 need to be added to DDP_COMPONENT_DITHER.

Then DITHER enum will become:
DDP_COMPONENT_DITHER0 and DDP_COMPONENT_DITHER1.

Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20220526102126.19756-5-jason-jh.lin@mediatek.com/
Signed-off-by: jason-jh.lin <jason-jh.lin@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>