dt-bindings: display: msm: sm6150-mdss: Add DisplayPort controller

SM6150 uses the same DisplayPort controller as SM8150, which is compatible
with SM8350. Add SM6150-specific compatible string for the DisplayPort
controller.

Signed-off-by: Xiangxu Yin <[e-mail]>
Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-by: Bjorn Andersson <[e-mail]>
Patchwork: https://patchwork.freedesktop.org/patch/685343/
Link: https://lore.kernel.org/r/2025110[e-mail]
Signed-off-by: Dmitry Baryshkov <[e-mail]>

Documentation/devicetree/bindings/display/msm/qcom,sm6150-mdss.yaml

···
       compatible:
         const: qcom,sm6150-dpu
 
+  "^displayport-controller@[0-9a-f]+$":
+    type: object
+    additionalProperties: true
+    properties:
+      compatible:
+        contains:
+          const: qcom,sm6150-dp
+
   "^dsi@[0-9a-f]+$":
     type: object
     additionalProperties: true