dt-bindings: power: reset: xilinx: Add bindings for ipi mailbox

 - compatible:		Must contain:	"xlnx,zynqmp-power"

 - interrupts:		Interrupt specifier

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Example

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Optional properties:

 - mbox-names	: Name given to channels seen in the 'mboxes' property.

		  "tx" - Mailbox corresponding to transmit path

		  "rx" - Mailbox corresponding to receive path

 - mboxes	: Standard property to specify a Mailbox. Each value of

		  the mboxes property should contain a phandle to the

		  mailbox controller device node and an args specifier

		  that will be the phandle to the intended sub-mailbox

		  child node to be used for communication. See

		  Documentation/devicetree/bindings/mailbox/mailbox.txt

		  for more details about the generic mailbox controller

		  and client driver bindings. Also see

		  Documentation/devicetree/bindings/mailbox/ \

		  xlnx,zynqmp-ipi-mailbox.txt for typical controller that

		  is used to communicate with this System controllers.

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Examples

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Example with interrupt method:

firmware {

	zynqmp_firmware: zynqmp-firmware {

		compatible = "xlnx,zynqmp-firmware";

		method = "smc";

		zynqmp_power: zynqmp-power {

			compatible = "xlnx,zynqmp-power";

			interrupts = <0 35 4>;

		};

	};

};

Example with IPI mailbox method:

firmware {

	zynqmp_firmware: zynqmp-firmware {

		zynqmp_power: zynqmp-power {

			compatible = "xlnx,zynqmp-power";

			interrupt-parent = <&gic>;

			interrupts = <0 35 4>;

			mboxes = <&ipi_mailbox_pmu0 0>,

				 <&ipi_mailbox_pmu0 1>;

			mbox-names = "tx", "rx";

		};

	};

};