mips: dts: Add support for Cisco SG220-26 switch

Signed-off-by: Bert Vermeulen <bert@biot.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/boot/dts/realtek/Makefile

+# SPDX-License-Identifier: GPL-2.0
+dtb-y	+= cisco_sg220-26.dtb

arch/mips/boot/dts/realtek/cisco_sg220-26.dts

+// SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause
+
+/dts-v1/;
+
+#include "rtl83xx.dtsi"
+#include "rtl838x.dtsi"
+
+/ {
+	model = "Cisco SG220-26";
+	compatible = "cisco,sg220-26", "realtek,rtl8382-soc";
+
+	chosen {
+		stdout-path = "serial0:9600n8";
+		bootargs = "earlycon console=ttyS0,9600";
+	};
+
+	memory@0 {
+		device_type = "memory";
+		reg = <0x0 0x8000000>;
+	};
+};
+
+&uart0 {
+	status = "okay";
+};