PM Domain Idle State Node:

A domain idle state node represents the state parameters that will be used to
select the state when there are no active components in the domain.

The state node has the following parameters -

- compatible:
	Usage: Required
	Value type: <string>
	Definition: Must be "domain-idle-state".

- entry-latency-us
	Usage: Required
	Value type: <prop-encoded-array>
	Definition: u32 value representing worst case latency in
		    microseconds required to enter the idle state.
		    The exit-latency-us duration may be guaranteed
		    only after entry-latency-us has passed.

- exit-latency-us
	Usage: Required
	Value type: <prop-encoded-array>
	Definition: u32 value representing worst case latency
		    in microseconds required to exit the idle state.

- min-residency-us
	Usage: Required
	Value type: <prop-encoded-array>
	Definition: u32 value representing minimum residency duration
		    in microseconds after which the idle state will yield
		    power benefits after overcoming the overhead in entering
i		    the idle state.
