arm64: dts: Add APM X-Gene 2 standby GPIO controller DTS entries

Add standby domain gpio controller for APM X-Gene 2 SoC platforms.
Signed-off-by: Duc Dang <dhdang@apm.com>

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

@@ -224,6 +224,21 @@ sata3: sata@1a400000 {
 			dma-coherent;
 		};
 
+		sbgpio: sbgpio@17001000{
+			compatible = "apm,xgene-gpio-sb";
+			reg = <0x0 0x17001000 0x0 0x400>;
+			#gpio-cells = <2>;
+			gpio-controller;
+			interrupts = <0x0 0x28 0x1>,
+				     <0x0 0x29 0x1>,
+				     <0x0 0x2a 0x1>,
+				     <0x0 0x2b 0x1>,
+				     <0x0 0x2c 0x1>,
+				     <0x0 0x2d 0x1>,
+				     <0x0 0x2e 0x1>,
+				     <0x0 0x2f 0x1>;
+		};
+
 		sgenet0: ethernet@1f610000 {
 			compatible = "apm,xgene2-sgenet";
 			status = "disabled";