arm64: zynqmp: PM: Add IRQ

PM callbacks are delivered to the NS OS. Let the PM driver handle the
IRQ and retrieve callback data from the secure HW.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/dts/zynqmp.dtsi

@@ -265,6 +265,8 @@
 	firmware {
 		compatible = "xlnx,zynqmp-pm";
 		method = "smc";
+		interrupt-parent = <&gic>;
+		interrupts = <0 35 4>;
 	};
 
 	timer {