dt-bindings: ili9881c: Allow port subnode

The ILI9881C is a DSI panel, which can be tied to a DSI controller
using OF graph port/endpoint. Allow the port subnode in the binding.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250904200130.168263-1-marek.vasut+renesas@mailbox.org

Author: Marek Vasut

Documentation/devicetree/bindings/display/panel/ilitek,ili9881c.yaml

@@ -31,6 +31,7 @@ properties:
     maxItems: 1
 
   backlight: true
+  port: true
   power-supply: true
   reset-gpios: true
   rotation: true