dt-bindings: media: mediatek: mdp3: Add support for MT8188 RDMA

Add a compatible for MediaTek MT8188 RDMA, which supports only a
subset of the MDP3 components of its similar MT8195 counterpart.

Signed-off-by: AngeloGioacchino Del Regno <[e-mail]>
Acked-by: Conor Dooley <[e-mail]>
Signed-off-by: Sebastian Fricke <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>

Documentation/devicetree/bindings/media/mediatek,mdp3-rdma.yaml

···
     oneOf:
       - enum:
           - mediatek,mt8183-mdp3-rdma
+          - mediatek,mt8188-mdp3-rdma
           - mediatek,mt8195-mdp3-rdma
           - mediatek,mt8195-vdo1-rdma
       - items: