1ARM PL061 GPIO controller
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3Required properties:
4- compatible : "arm,pl061", "arm,primecell"
5- #gpio-cells : Should be two. The first cell is the pin number and the
6  second cell is used to specify optional parameters:
7  - bit 0 specifies polarity (0 for normal, 1 for inverted)
8- gpio-controller : Marks the device node as a GPIO controller.
9- interrupts : Interrupt mapping for GPIO IRQ.
10- gpio-ranges : Interaction with the PINCTRL subsystem.
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