soc: mediatek: add DDP_DOMPONENT_DITHER0 enum for mt8195 vdosys0

soc: mediatek: add DDP_DOMPONENT_DITHER0 enum for mt8195 vdosys0

The mmsys routing table of mt8195 vdosys0 has 2 DITHER components,
so mmsys need to add DDP_COMPONENT_DITHER1 and change all usages of
DITHER enum form DDP_COMPONENT_DITHER to DDP_COMPONENT_DITHER0.

But its header need to keep DDP_COMPONENT_DITHER enum
until drm/mediatek also changed it.

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>
Link: https://lore.kernel.org/r/20220419094143.9561-7-jason-jh.lin@mediatek.com
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>