Optional properties:
- enable-gpio : GPIO to use to enable/disable the regulator.
- gpios : GPIO group used to control voltage.
+- gpios-states : gpios pin's initial states array. 0: LOW, 1: HIGH.
+ defualt is LOW if nothing is specified.
- startup-delay-us : Startup time in microseconds.
- enable-active-high : Polarity of GPIO is active high (default is low).
+- regulator-type : Specifies what is being regulated, must be either
+ "voltage" or "current", defaults to current.
Any property defined as part of the core regulator binding defined in
regulator.txt can also be used.