arm64: dts: rockchip: set rockpro64 usbc dr_mode as host

The usb-c port on the rockpro64 does not detect devices reliably when in otg mode.
Setting the mode to "host" allows the port to work reliably.
This aligns with the pinebook-pro configuration.
Signed-off-by: Peter Geis <pgwipeout@gmail.com>
Link: https://lore.kernel.org/r/20200614142950.1120694-1-pgwipeout@gmail.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3399-rockpro64.dtsi

@@ -795,7 +795,7 @@ &usbdrd3_0 {
 
 &usbdrd_dwc3_0 {
 	status = "okay";
-	dr_mode = "otg";
+	dr_mode = "host";
 };
 
 &usbdrd3_1 {