board: rockchip: Add FriendlyElec NanoPi R6S

The NanoPi R6S is a SBC by FriendlyElec based on the Rockchip RK3588s.
It comes with 4GB or 8GB of RAM, a microSD card slot, 32GB eMMC storage,
one RTL8211F 1GbE and two RTL8125 2.5GbE Ethernet ports, one USB 2.0
Type-A and one USB 3.0 Type-A port, a HDMI port, a 12-pin GPIO FPC
connector, a fan connector, IR receiver as well as some buttons and LEDs.

Add initial support for this board using the upstream devicetree sources.

Kernel commit:
f1b11f43b3e9 ("arm64: dts: rockchip: Add support for NanoPi R6S")

Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Sebastian Kropatsch <seb-dev@mail.de>
diff --git a/include/configs/nanopi-r6s-rk3588s.h b/include/configs/nanopi-r6s-rk3588s.h
new file mode 100644
index 0000000..a1b1978
--- /dev/null
+++ b/include/configs/nanopi-r6s-rk3588s.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#ifndef __NANOPI_R6S_RK3588S_H
+#define __NANOPI_R6S_RK3588S_H
+
+#define ROCKCHIP_DEVICE_SETTINGS \
+		"stdout=serial,vidconsole\0" \
+		"stderr=serial,vidconsole\0"
+
+#include <configs/rk3588_common.h>
+
+#endif /* __NANOPI_R6S_RK3588S_H */