dt-bindings: display: imx: add deprecated property 'port' and 'display-timings'

Add deprecated property 'port' and 'display-timings' for i.MX5 SoCs (over
15 years) to fix below CHECK_DTBS warnings:
  arm/boot/dts/nxp/imx/imx51-apf51dev.dtb: disp1 (fsl,imx-parallel-display): 'display-timings', 'port' do not match any of the regexes: '^pinctrl-[0-9]+$'
        from schema $id: http://devicetree.org/schemas/display/imx/fsl,imx-parallel-display.yaml

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20260511220924.1905571-1-Frank.Li@nxp.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

Documentation/devicetree/bindings/display/imx/fsl,imx-parallel-display.yaml

@@ -42,6 +42,17 @@ properties:
     unevaluatedProperties: false
     description: output port connected to a panel
 
+  port:
+    $ref: /schemas/graph.yaml#/properties/port
+    unevaluatedProperties: false
+    deprecated: true
+    description: input port connected to the IPU display interface, see port@0
+
+  display-timings:
+    $ref: /schemas/display/panel/display-timings.yaml#
+    unevaluatedProperties: false
+    deprecated: true
+
 required:
   - compatible