arm64: dts: hi3660: Add mailbox node

Add the mailbox controller node for hi3660 platform.
Signed-off-by: NKaihua Zhong <zhongkaihua@huawei.com>
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Signed-off-by: NWei Xu <xuwei5@hisilicon.com>

arch/arm64/boot/dts/hisilicon/hi3660.dtsi

@@ -274,6 +274,14 @@
 			#reset-cells = <2>;
 		};
 
+		mailbox: mailbox@e896b000 {
+			compatible = "hisilicon,hi3660-mbox";
+			reg = <0x0 0xe896b000 0x0 0x1000>;
+			interrupts = <GIC_SPI 192 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 193 IRQ_TYPE_LEVEL_HIGH>;
+			#mbox-cells = <3>;
+		};
+
 		dual_timer0: timer@fff14000 {
 			compatible = "arm,sp804", "arm,primecell";
 			reg = <0x0 0xfff14000 0x0 0x1000>;