NVIDIA Tegra PMC LED Soft Blink driver

Required properties:
- compatible: "nvidia,tegra210b01-pwm-led-soft-blink"
- #pwm-cells: should be 2. See pwm.txt in this directory for a description of
  the cells format.

Optional properties:
- pwm,led-breathing-ramp-time-ns: led breathing ramp up and ramp down time
- pwm,led-breathing-short-period-ns: led breathing short low period, breath out
	duration between two cones.

Example:

	tegra-pmc-blink-pwm {
		compatible = "nvidia,tegra210b01-pwm-led-soft-blink";
		pwm,led-breathing-ramp-time-ns = <240000000>;
		pwm,led-breathing-short-period-ns = <100000000>;
                #pwm-cells = <2>;
	};