arm64: dts: zynqmp: Add missing lpd watchdog node

Xilinx ZynqMP SoC has FPD (Full Power Domain) and LPD (Low Power Domain)
watchdogs. There are cases where also LPD WDT should be used by Arm cores
that's why list it with disabled status.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/0489a1d5528614f1d570ea153d38b813f0c1eb9f.1611224800.git.michal.simek@xilinx.com

arch/arm64/boot/dts/xilinx/zynqmp-clk-ccf.dtsi

@@ -223,3 +223,7 @@ &usb1 {
 &watchdog0 {
 	clocks = <&zynqmp_clk WDT>;
 };
+
+&lpd_watchdog {
+	clocks = <&zynqmp_clk LPD_WDT>;
+};

arch/arm64/boot/dts/xilinx/zynqmp.dtsi

@@ -786,5 +786,14 @@ watchdog0: watchdog@fd4d0000 {
 			reg = <0x0 0xfd4d0000 0x0 0x1000>;
 			timeout-sec = <10>;
 		};
+
+		lpd_watchdog: watchdog@ff150000 {
+			compatible = "cdns,wdt-r1p2";
+			status = "disabled";
+			interrupt-parent = <&gic>;
+			interrupts = <0 52 1>;
+			reg = <0x0 0xff150000 0x0 0x1000>;
+			timeout-sec = <10>;
+		};
 	};
 };