dt-bindings: display: ltk500hd1829: add port property

The panel can be connected to via graph nodes, so allow the port property.

Signed-off-by: Heiko Stuebner <heiko.stuebner@cherry.de>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20250430082850.244199-3-heiko@sntech.de
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

Documentation/devicetree/bindings/display/panel/leadtek,ltk500hd1829.yaml

@@ -22,6 +22,7 @@ properties:
     maxItems: 1
 
   backlight: true
+  port: true
   reset-gpios: true
   iovcc-supply:
     description: regulator that supplies the iovcc voltage