arm64: dts: renesas: aistarvision-mipi-adapter-2.1: Fix CSI40 ports

Fix the DTS schema by explicitly stating that the input is port@0. This
fixes a schema validation error but has no runtime effect as the default
port number is 0 if not specified.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20210421150221.3202955-2-niklas.soderlund+renesas@ragnatech.seSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/arm64/boot/dts/renesas/r8a774c0-ek874-mipi-2.1.dts

@@ -33,7 +33,7 @@ &csi40 {
 	status = "okay";
 
 	ports {
-		port {
+		port@0 {
 			csi40_in: endpoint {
 				clock-lanes = <0>;
 				data-lanes = <1 2>;