mips: mt76xx: Add GPIO DT nodes to mt7628a.dtsi

Add the GPIO DT nodes to the DTS file.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

arch/mips/dts/mt7628a.dtsi

@@ -71,6 +71,38 @@
 			reg = <0x300 0x100>;
 		};
 
+		gpio@600 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			compatible = "mtk,mt7628-gpio", "mtk,mt7621-gpio";
+			reg = <0x600 0x100>;
+
+			interrupt-parent = <&intc>;
+			interrupts = <6>;
+
+			gpio0: bank@0 {
+				reg = <0>;
+				compatible = "mtk,mt7621-gpio-bank";
+				gpio-controller;
+				#gpio-cells = <2>;
+			};
+
+			gpio1: bank@1 {
+				reg = <1>;
+				compatible = "mtk,mt7621-gpio-bank";
+				gpio-controller;
+				#gpio-cells = <2>;
+			};
+
+			gpio2: bank@2 {
+				reg = <2>;
+				compatible = "mtk,mt7621-gpio-bank";
+				gpio-controller;
+				#gpio-cells = <2>;
+			};
+		};
+
 		spi0: spi@b00 {
 			compatible = "ralink,mt7621-spi";
 			reg = <0xb00 0x40>;