arm64: dts: rockchip: Simplify mipi_out endpoint on rk3399 RP64 dtso

The only thing actually added here is a single endpoint on mipi_out,
which is already defined in rk3399-base.dtsi, so it's simpler to just
reference that phandle, which allows the removal of several properties.

Signed-off-by: Diederik de Haas <didi.debian@cknow.org>
Link: https://lore.kernel.org/r/20250709132323.128757-7-didi.debian@cknow.org
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Author: diederikdehaas

arch/arm64/boot/dts/rockchip/rk3399-rockpro64-screen.dtso

@@ -52,19 +52,6 @@
 	#size-cells = <0>;
 	status = "okay";
 
-	ports {
-		#address-cells = <1>;
-		#size-cells = <0>;
-
-		mipi_out: port@1 {
-			reg = <1>;
-
-			mipi_out_panel: endpoint {
-				remote-endpoint = <&mipi_in_panel>;
-			};
-		};
-	};
-
 	mipi_panel: panel@0 {
 		compatible = "feiyang,fy07024di26a30d";
 		reg = <0>;
@@ -80,6 +67,12 @@
 	};
 };
 
+&mipi_out {
+	mipi_out_panel: endpoint {
+		remote-endpoint = <&mipi_in_panel>;
+	};
+};
+
 &pwm0 {
 	status = "okay";
 };