dt-bindings: display: mediatek: aal: add compatible for MT8195

Add a compatible string for the AAL block in MediaTek MT8195 that
is controlled by MDP3.

Signed-off-by: Moudy Ho <[e-mail]>
Acked-by: Conor Dooley <[e-mail]>
Reviewed-by: AngeloGioacchino Del Regno <[e-mail]>
Signed-off-by: AngeloGioacchino Del Regno <[e-mail]>

Documentation/devicetree/bindings/display/mediatek/mediatek,aal.yaml

···
       - enum:
           - mediatek,mt8173-disp-aal
           - mediatek,mt8183-disp-aal
+          - mediatek,mt8195-mdp3-aal
       - items:
           - enum:
               - mediatek,mt2712-disp-aal