Documentation: dt: binding: fsl: add devicetree binding for describing RCPM

* Run Control and Power Management

-------------------------------------------

The RCPM performs all device-level tasks associated with device run control

and power management.

Required properites:

  - reg : Offset and length of the register set of the RCPM block.

  - fsl,#rcpm-wakeup-cells : The number of IPPDEXPCR register cells in the

	fsl,rcpm-wakeup property.

  - compatible : Must contain a chip-specific RCPM block compatible string

	and (if applicable) may contain a chassis-version RCPM compatible

	string. Chip-specific strings are of the form "fsl,<chip>-rcpm",

	such as:

	* "fsl,p2041-rcpm"

	* "fsl,p5020-rcpm"

	* "fsl,t4240-rcpm"

	Chassis-version strings are of the form "fsl,qoriq-rcpm-<version>",

	such as:

	* "fsl,qoriq-rcpm-1.0": for chassis 1.0 rcpm

	* "fsl,qoriq-rcpm-2.0": for chassis 2.0 rcpm

	* "fsl,qoriq-rcpm-2.1": for chassis 2.1 rcpm

All references to "1.0" and "2.0" refer to the QorIQ chassis version to

which the chip complies.

Chassis Version		Example Chips

---------------		-------------------------------

1.0				p4080, p5020, p5040, p2041, p3041

2.0				t4240, b4860, b4420

2.1				t1040, ls1021

Example:

The RCPM node for T4240:

	rcpm: global-utilities@e2000 {

		compatible = "fsl,t4240-rcpm", "fsl,qoriq-rcpm-2.0";

		reg = <0xe2000 0x1000>;

		fsl,#rcpm-wakeup-cells = <2>;

	};

* Freescale RCPM Wakeup Source Device Tree Bindings

-------------------------------------------

Required fsl,rcpm-wakeup property should be added to a device node if the device

can be used as a wakeup source.

  - fsl,rcpm-wakeup: Consists of a phandle to the rcpm node and the IPPDEXPCR

	register cells. The number of IPPDEXPCR register cells is defined in

	"fsl,#rcpm-wakeup-cells" in the rcpm node. The first register cell is

	the bit mask that should be set in IPPDEXPCR0, and the second register

	cell is for IPPDEXPCR1, and so on.

	Note: IPPDEXPCR(IP Powerdown Exception Control Register) provides a

	mechanism for keeping certain blocks awake during STANDBY and MEM, in

	order to use them as wake-up sources.

Example:

	lpuart0: serial@2950000 {

		compatible = "fsl,ls1021a-lpuart";

		reg = <0x0 0x2950000 0x0 0x1000>;

		interrupts = <GIC_SPI 80 IRQ_TYPE_LEVEL_HIGH>;

		clocks = <&sysclk>;

		clock-names = "ipg";

		fsl,rcpm-wakeup = <&rcpm 0x0 0x40000000>;

	};