arm64: dts: marvell: uDPU: add missing SoC compatible

According to the bindings, all boards using Armada 37xx SoC-s must have
"marvell,armada3710" compatible while 3720 based ones should also have
"marvell,armada3720" before it.
Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>

arch/arm64/boot/dts/marvell/armada-3720-uDPU.dts

@@ -16,7 +16,7 @@
 
 / {
 	model = "Methode uDPU Board";
-	compatible = "methode,udpu", "marvell,armada3720";
+	compatible = "methode,udpu", "marvell,armada3720", "marvell,armada3710";
 
 	chosen {
 		stdout-path = "serial0:115200n8";