arm: colibri-vf: Enable serial support

- Enable lpuart support on Toradex Colibri VF50/VF61
- Use UART0 for stdout.

Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/arm/dts/vf-colibri.dtsi

@@ -5,6 +5,12 @@
  */
 #include "vf.dtsi"
 
+/ {
+	chosen {
+		stdout-path = &uart0;
+	};
+};
+
 &dspi1 {
 	status = "okay";
 	bus-num = <1>;
@@ -14,3 +20,7 @@
 		spi-max-frequency = <50000000>;
 	};
 };
+
+&uart0 {
+	status = "okay";
+};