mfd: da9062: dt: Add bindings for DA9062 driver

* Dialog DA9062 Power Management Integrated Circuit (PMIC)

DA9062 consists of a large and varied group of sub-devices:

Device                   Supply Names    Description

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

da9062-regulator        :               : LDOs & BUCKs

da9062-watchdog         :               : Watchdog Timer

======

Required properties:

- compatible : Should be "dlg,da9062".

- reg : Specifies the I2C slave address (this defaults to 0x58 but it can be

  modified to match the chip's OTP settings).

- interrupt-parent : Specifies the reference to the interrupt controller for

  the DA9062.

- interrupts : IRQ line information.

- interrupt-controller

See Documentation/devicetree/bindings/interrupt-controller/interrupts.txt for

further information on IRQ bindings.

Sub-nodes:

- regulators : This node defines the settings for the LDOs and BUCKs. The

  DA9062 regulators are bound using their names listed below:

    buck1    : BUCK_1

    buck2    : BUCK_2

    buck3    : BUCK_3

    buck4    : BUCK_4

    ldo1     : LDO_1

    ldo2     : LDO_2

    ldo3     : LDO_3

    ldo4     : LDO_4

  The component follows the standard regulator framework and the bindings

  details of individual regulator device can be found in:

  Documentation/devicetree/bindings/regulator/regulator.txt

- watchdog: This node defines the settings for the watchdog driver associated

  with the DA9062 PMIC. The compatible = "dlg,da9062-watchdog" should be added

  if a node is created.

Example:

	pmic0: da9062@58 {

		compatible = "dlg,da9062";

		reg = <0x58>;

		interrupt-parent = <&gpio6>;

		interrupts = <11 IRQ_TYPE_LEVEL_LOW>;

		interrupt-controller;

		watchdog {

			compatible = "dlg,da9062-watchdog";

		};

		regulators {

			DA9062_BUCK1: buck1 {

				regulator-name = "BUCK1";

				regulator-min-microvolt = <300000>;

				regulator-max-microvolt = <1570000>;

				regulator-min-microamp = <500000>;

				regulator-max-microamp = <2000000>;

				regulator-boot-on;

			};

			DA9062_LDO1: ldo1 {

				regulator-name = "LDO_1";

				regulator-min-microvolt = <900000>;

				regulator-max-microvolt = <3600000>;

				regulator-boot-on;

			};

		};

	};