Maxim MAX30100 heart rate and pulse oximeter sensor

* https://datasheets.maximintegrated.com/en/ds/MAX30100.pdf

Required properties:
  - compatible: must be "maxim,max30100"
  - reg: the I2C address of the sensor
  - interrupts: the sole interrupt generated by the device

  Refer to interrupt-controller/interrupts.txt for generic
  interrupt client node bindings.

Optional properties:
  - maxim,led-current-microamp: configuration for LED current in microamperes
    while the engine is running. First indexed value is the configuration for
    the RED LED, and second value is for the IR LED.

    Refer to the datasheet for the allowed current values.

Example:

max30100@57 {
	compatible = "maxim,max30100";
	reg = <0x57>;
	maxim,led-current-microamp = <24000 50000>;
	interrupt-parent = <&gpio1>;
	interrupts = <16 2>;
};
