arm64: dts: marvell: mcbin: add an stdout-path

This patch adds an stdout-path to the mcbin device tree. This allows to
use earlycon.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

arch/arm64/boot/dts/marvell/armada-8040-mcbin.dts

@@ -53,6 +53,10 @@ / {
 	compatible = "marvell,armada8040-mcbin", "marvell,armada8040",
 			"marvell,armada-ap806-quad", "marvell,armada-ap806";
 
+	chosen {
+		stdout-path = "serial0:115200n8";
+	};
+
 	memory@00000000 {
 		device_type = "memory";
 		reg = <0x0 0x0 0x0 0x80000000>;