ARM: dts: imx: Add missing chosen/stdout-path

This makes it possible to enable earlycon for debugging by just passing
an empty "earlycon" argument on the kernel command-line.
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/boot/dts/imx6qdl-sabreauto.dtsi

@@ -6,6 +6,10 @@
 #include <dt-bindings/gpio/gpio.h>
 
 / {
+	chosen {
+		stdout-path = &uart4;
+	};
+
 	memory@10000000 {
 		reg = <0x10000000 0x80000000>;
 	};

arch/arm/boot/dts/imx6sl-evk.dts

@@ -12,6 +12,10 @@ / {
 	model = "Freescale i.MX6 SoloLite EVK Board";
 	compatible = "fsl,imx6sl-evk", "fsl,imx6sl";
 
+	chosen {
+		stdout-path = &uart1;
+	};
+
 	memory@80000000 {
 		reg = <0x80000000 0x40000000>;
 	};

arch/arm/boot/dts/imx6sll-evk.dts

@@ -15,6 +15,10 @@ / {
 	model = "Freescale i.MX6SLL EVK Board";
 	compatible = "fsl,imx6sll-evk", "fsl,imx6sll";
 
+	chosen {
+		stdout-path = &uart1;
+	};
+
 	memory@80000000 {
 		reg = <0x80000000 0x80000000>;
 	};

arch/arm/boot/dts/imx7d-sdb.dts

@@ -10,6 +10,10 @@ / {
 	model = "Freescale i.MX7 SabreSD Board";
 	compatible = "fsl,imx7d-sdb", "fsl,imx7d";
 
+	chosen {
+		stdout-path = &uart1;
+	};
+
 	memory@80000000 {
 		reg = <0x80000000 0x80000000>;
 	};