ARM: dts: hisilicon: fix the system controller compatible nodes

The DT binding for Hisilicon system controllers require to have a
"syscon" compatible string.

Signed-off-by: Zhen Lei <[e-mail]>
Signed-off-by: Wei Xu <[e-mail]>

arch/arm/boot/dts/hi3620.dtsi

···
 		};
 
 		sysctrl: system-controller@802000 {
-			compatible = "hisilicon,sysctrl";
+			compatible = "hisilicon,sysctrl", "syscon";
 			#address-cells = <1>;
 			#size-cells = <1>;
 			ranges = <0 0x802000 0x1000>;

arch/arm/boot/dts/hip04.dtsi

···
 		};
 
 		sysctrl: sysctrl {
-			compatible = "hisilicon,sysctrl";
+			compatible = "hisilicon,sysctrl", "syscon";
 			reg = <0x3e00000 0x00100000>;
 		};