ARM: dts: exynos: Add serial path for Rinato board to get earlycon support

Add 'chosen' node with 'stdout-path' property to instruct kernel which
serial driver should be used for kernel console/logs. This allows to
enable earlycon messages by adding just 'earlycon' parameter to kernel
command line.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>

arch/arm/boot/dts/exynos3250-rinato.dts

@@ -24,6 +24,10 @@
 		i2c7 = &i2c_max77836;
 	};
 
+	chosen {
+		stdout-path = &serial_1;
+	};
+
 	memory@40000000 {
 		device_type = "memory";
 		reg =  <0x40000000 0x1ff00000>;