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

Add standby domain gpio controller for APM X-Gene SoC platform.

Signed-off-by: Y Vo <[e-mail]>
Acked-by: Linus Walleij <[e-mail]>
Signed-off-by: Kevin Hilman <[e-mail]>

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

···
 			phy-names = "sata-phy";
 		};
 
+		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>;
+		};
+
 		rtc: rtc@10510000 {
 			compatible = "apm,xgene-rtc";
 			reg = <0x0 0x10510000 0x0 0x400>;