ARM: dts: am57xx: Add stdout-path property

Add stdout-path property in /chosen node so that earlycon can be
used by just adding earlycon in bootargs.
Signed-off-by: NLokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

arch/arm/boot/dts/am57xx-beagle-x15-common.dtsi

@@ -22,6 +22,10 @@
 		display0 = &hdmi0;
 	};
 
+	chosen {
+		stdout-path = &uart3;
+	};
+
 	memory@0 {
 		device_type = "memory";
 		reg = <0x0 0x80000000 0x0 0x80000000>;

arch/arm/boot/dts/am57xx-idk-common.dtsi

@@ -14,6 +14,10 @@
 		rtc1 = &rtc;
 	};
 
+	chosen {
+		stdout-path = &uart3;
+	};
+
 	vmain: fixedregulator-vmain {
 		compatible = "regulator-fixed";
 		regulator-name = "VMAIN";