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 <[email protected]>
Reviewed-by: AngeloGioacchino Del Regno <[email protected]>
Reviewed-by: Rex-BC Chen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Matthias Brugger <[email protected]>