ARM: dts: stm32: fix warnings on stm32f469-disco board

Several warnings appear when building and checking stm32f429 device-tree:

arch/arm/boot/dts/stm32f469-disco.dts:182.28-184.5: Warning (unit_address_vs_reg): /soc/display-controller@40016800/port/endpoint@0: node has a unit name, but no reg or ranges property

.../arch/arm/boot/dts/stm32f469-disco.dtb: dsi@40016c00: Unevaluated properties are not allowed ('panel-dsi@0' was unexpected)
	From schema: .../Documentation/devicetree/bindings/display/st,stm32-dsi.yaml

Fix those.
Signed-off-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

arch/arm/boot/dts/stm32f469-disco.dts

@@ -160,7 +160,7 @@ dsi_out: endpoint {
 		};
 	};
 
-	panel-dsi@0 {
+	panel@0 {
 		compatible = "orisetech,otm8009a";
 		reg = <0>; /* dsi virtual channel (0..3) */
 		reset-gpios = <&gpioh 7 GPIO_ACTIVE_LOW>;
@@ -179,7 +179,7 @@ &ltdc {
 	status = "okay";
 
 	port {
-		ltdc_out_dsi: endpoint@0 {
+		ltdc_out_dsi: endpoint {
 			remote-endpoint = <&dsi_in>;
 		};
 	};