TI BQ24190 Li-Ion Battery Charger

Required properties:
- compatible: contains one of the following:
    * "ti,bq24190"
    * "ti,bq24192i"
- reg: integer, I2C address of the charger.
- interrupts[-extended]: configuration for charger INT pin.

Optional properties:
- monitored-battery: phandle of battery characteristics devicetree node
  The charger uses the following battery properties:
    + precharge-current-microamp: maximum charge current during precharge
      phase (typically 20% of battery capacity).
    + charge-term-current-microamp: a charge cycle terminates when the
      battery voltage is above recharge threshold, and the current is below
      this setting (typically 10% of battery capacity).
  See also Documentation/devicetree/bindings/power/supply/battery.txt
- ti,system-minimum-microvolt: when power is connected and the battery is below
  minimum system voltage, the system will be regulated above this setting.

Notes:
- Some circuit boards wire the chip's "OTG" pin high (enabling 500mA default
  charge current on USB SDP ports, among other features). To simulate this on
  boards that wire the pin to a GPIO, set a gpio-hog.

Example:

	bat: battery {
		compatible = "simple-battery";
		precharge-current-microamp = <256000>;
		charge-term-current-microamp = <128000>;
		// etc.
	};

	bq24190: charger@6a {
		compatible = "ti,bq24190";
		reg = <0x6a>;
		interrupts-extended = <&gpiochip 10 IRQ_TYPE_EDGE_FALLING>;
		monitored-battery = <&bat>;
		ti,system-minimum-microvolt = <3200000>;
	};

	&twl_gpio {
		otg {
			gpio-hog;
			gpios = <6 0>;
			output-high;
			line-name = "otg-gpio";
		};
	};