mfd: tc3589x: Add device tree bindings

* Toshiba TC3589x multi-purpose expander

The Toshiba TC3589x series are I2C-based MFD devices which may expose the

following built-in devices: gpio, keypad, rotator (vibrator), PWM (for

e.g. LEDs or vibrators) The included models are:

- TC35890

- TC35892

- TC35893

- TC35894

- TC35895

- TC35896

Required properties:

 - compatible : must be "toshiba,tc35890", "toshiba,tc35892", "toshiba,tc35893",

   "toshiba,tc35894", "toshiba,tc35895" or "toshiba,tc35896"

 - reg : I2C address of the device

 - interrupt-parent : specifies which IRQ controller we're connected to

 - interrupts : the interrupt on the parent the controller is connected to

 - interrupt-controller : marks the device node as an interrupt controller

 - #interrupt-cells : should be <1>, the first cell is the IRQ offset on this

   TC3589x interrupt controller.

Optional nodes:

- GPIO

  This GPIO module inside the TC3589x has 24 (TC35890, TC35892) or 20

  (other models) GPIO lines.

 - compatible : must be "toshiba,tc3589x-gpio"

 - interrupts : interrupt on the parent, which must be the tc3589x MFD device

 - interrupt-controller : marks the device node as an interrupt controller

 - #interrupt-cells : should be <2>, the first cell is the IRQ offset on this

   TC3589x GPIO interrupt controller, the second cell is the interrupt flags

   in accordance with <dt-bindings/interrupt-controller/irq.h>. The following

   flags are valid:

   - IRQ_TYPE_LEVEL_LOW

   - IRQ_TYPE_LEVEL_HIGH

   - IRQ_TYPE_EDGE_RISING

   - IRQ_TYPE_EDGE_FALLING

   - IRQ_TYPE_EDGE_BOTH

 - gpio-controller : marks the device node as a GPIO controller

 - #gpio-cells : should be <2>, the first cell is the GPIO offset on this

   GPIO controller, the second cell is the flags.

- Keypad

  This keypad is the same on all variants, supporting up to 96 different

  keys. The linux-specific properties are modeled on those already existing

  in other input drivers.

 - compatible : must be "toshiba,tc3589x-keypad"

 - debounce-delay-ms : debounce interval in milliseconds

 - keypad,num-rows : number of rows in the matrix, see

   bindings/input/matrix-keymap.txt

 - keypad,num-columns : number of columns in the matrix, see

   bindings/input/matrix-keymap.txt

 - linux,keymap: the definition can be found in

   bindings/input/matrix-keymap.txt

 - linux,no-autorepeat: do no enable autorepeat feature.

 - linux,wakeup: use any event on keypad as wakeup event.

Example:

tc35893@44 {

	compatible = "toshiba,tc35893";

	reg = <0x44>;

	interrupt-parent = <&gpio6>;

	interrupts = <26 IRQ_TYPE_EDGE_RISING>;

	interrupt-controller;

	#interrupt-cells = <1>;

	tc3589x_gpio {

		compatible = "toshiba,tc3589x-gpio";

		interrupts = <0>;

		interrupt-controller;

		#interrupt-cells = <2>;

		gpio-controller;

		#gpio-cells = <2>;

	};

	tc3589x_keypad {

		compatible = "toshiba,tc3589x-keypad";

		interrupts = <6>;

		debounce-delay-ms = <4>;

		keypad,num-columns = <8>;

		keypad,num-rows = <8>;

		linux,no-autorepeat;

		linux,wakeup;

		linux,keymap = <0x0301006b

				0x04010066

				0x06040072

				0x040200d7

				0x0303006a

				0x0205000e

				0x0607008b

				0x0500001c

				0x0403000b

				0x03040034

				0x05020067

				0x0305006c

				0x040500e7

				0x0005009e

				0x06020073

				0x01030039

				0x07060069

				0x050500d9>;

	};

};