arm64: dts: Add APM X-Gene v2 SoC Designware GPIO controller DTS entry

This patch adds Designware GPIO controller DTS node for APM
X-Gene v2 platforms.
Signed-off-by: Duc Dang <dhdang@apm.com>

arch/arm64/boot/dts/apm/apm-shadowcat.dtsi

@@ -431,6 +431,21 @@ gfcgpio: gfcgpio@1f63c000 {
 			#gpio-cells = <2>;
 		};
 
+		dwgpio: dwgpio@1c024000 {
+			compatible = "snps,dw-apb-gpio";
+			reg = <0x0 0x1c024000 0x0 0x1000>;
+			reg-io-width = <4>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			porta: gpio-controller@0 {
+				compatible = "snps,dw-apb-gpio-port";
+				gpio-controller;
+				snps,nr-gpios = <32>;
+				reg = <0>;
+			};
+		};
+
 		sbgpio: sbgpio@17001000{
 			compatible = "apm,xgene-gpio-sb";
 			reg = <0x0 0x17001000 0x0 0x400>;