Documentation: dt: wireless: Add wl1251

* Texas Instruments wl1251 wireless lan controller

The wl1251 chip can be connected via SPI or via SDIO. This

document describes the binding for the SPI connected chip.

Required properties:

- compatible :        Should be "ti,wl1251"

- reg :               Chip select address of device

- spi-max-frequency : Maximum SPI clocking speed of device in Hz

- interrupts :        Should contain interrupt line

- interrupt-parent :  Should be the phandle for the interrupt controller

                      that services interrupts for this device

- vio-supply :        phandle to regulator providing VIO

- ti,power-gpio :     GPIO connected to chip's PMEN pin

Optional properties:

- ti,wl1251-has-eeprom : boolean, the wl1251 has an eeprom connected, which

                         provides configuration data (calibration, MAC, ...)

- Please consult Documentation/devicetree/bindings/spi/spi-bus.txt

  for optional SPI connection related properties,

Examples:

&spi1 {

	wl1251@0 {

		compatible = "ti,wl1251";

		reg = <0>;

		spi-max-frequency = <48000000>;

		spi-cpol;

		spi-cpha;

		interrupt-parent = <&gpio2>;

		interrupts = <10 IRQ_TYPE_NONE>; /* gpio line 42 */

		vio-supply = <&vio>;

		ti,power-gpio = <&gpio3 23 GPIO_ACTIVE_HIGH>; /* 87 */

	};

};