ARM: dts: Enable earlycon stdout path for duovero

As long as the kernel cmdline has "earlycon" in it, this allows
seeing debug messages earlier and does not require DEBUG_LL to
be enabled.
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/boot/dts/omap4-duovero.dtsi

@@ -12,6 +12,10 @@ / {
 	model = "Gumstix Duovero";
 	compatible = "gumstix,omap4-duovero", "ti,omap4430", "ti,omap4";
 
+	chosen {
+		stdout-path = &uart3;
+	};
+
 	memory@80000000 {
 		device_type = "memory";
 		reg = <0x80000000 0x40000000>; /* 1 GB */