dt-bindings: display: mediatek: dsi: Add compatible for MediaTek MT6795

Add a compatible string for MediaTek Helio X10 MT6795, using the same
DSI block as MT8173.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20230412112739.160376-6-angelogioacchino.delregno@collabora.com/Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

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

@@ -22,13 +22,18 @@ allOf:
 
 properties:
   compatible:
-    enum:
+    oneOf:
+      - enum:
           - mediatek,mt2701-dsi
           - mediatek,mt7623-dsi
           - mediatek,mt8167-dsi
           - mediatek,mt8173-dsi
           - mediatek,mt8183-dsi
           - mediatek,mt8186-dsi
+      - items:
+          - enum:
+              - mediatek,mt6795-dsi
+          - const: mediatek,mt8173-dsi
 
   reg:
     maxItems: 1