arm64: dts: rockchip: Add chosen node for ROCK-Pi N8

Add chosen node in -u-boot.dtsi for ROCK-Pi N8 board.

This will help to get serial out messages.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Kever Yang<kever.yang@rock-chips.com>
diff --git a/arch/arm/dts/rk3288-rock-pi-n8-u-boot.dtsi b/arch/arm/dts/rk3288-rock-pi-n8-u-boot.dtsi
index e9d7404..538607d 100644
--- a/arch/arm/dts/rk3288-rock-pi-n8-u-boot.dtsi
+++ b/arch/arm/dts/rk3288-rock-pi-n8-u-boot.dtsi
@@ -5,6 +5,12 @@
 
 #include "rk3288-u-boot.dtsi"
 
+/{
+	chosen {
+		stdout-path = &uart2;
+	};
+};
+
 &dmc {
 	rockchip,pctl-timing = <0x215 0xc8 0x0 0x35 0x26 0x2 0x70 0x2000d
 		0x6 0x0 0x8 0x4 0x17 0x24 0xd 0x6