arm64: dts: allwinner: a64: Add msgbox node

The A64 SoC contains a message box that can be used to send messages and
interrupts back and forth between the ARM application CPUs and the ARISC
coprocessor. Add a device tree node for it.
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi

@@ -557,6 +557,16 @@ crypto: crypto@1c15000 {
 			resets = <&ccu RST_BUS_CE>;
 		};
 
+		msgbox: mailbox@1c17000 {
+			compatible = "allwinner,sun50i-a64-msgbox",
+				     "allwinner,sun6i-a31-msgbox";
+			reg = <0x01c17000 0x1000>;
+			clocks = <&ccu CLK_BUS_MSGBOX>;
+			resets = <&ccu RST_BUS_MSGBOX>;
+			interrupts = <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH>;
+			#mbox-cells = <1>;
+		};
+
 		usb_otg: usb@1c19000 {
 			compatible = "allwinner,sun8i-a33-musb";
 			reg = <0x01c19000 0x0400>;