Add pmstates array generated from global power-states DT node children,
vs. current per-CPU only pmstates array (SMP platforms only).

Add helper functions for retrieving the index of a global/per-CPU
power-state array element.
These functions are intended to faciliate easier processing of similar
PM data structures generated from the same DT power-states nodes.

Signed-off-by: Kenneth J. Miller <[email protected]>

Replace individual entry and exit callbacks with a singular callback,
with a separate direction bit field to indicate whether the struct
applies to state entry/exit, or both.

Add a void pointer to provide optional context for the callback.

Replace the singular pm_notifiers slist with individual power state-
specific slists, generated from DT power-states definitions on SMP, and
cpu-power-states on single-CPU platforms.

Un/register functions now take a power (sub)state as a parameter, in
addition to the usual pm_notifier struct; used to place the notifier
into the correct list.

Signed-off-by: Kenneth J. Miller <[email protected]>

Update pm tests and sample that make use of pm_notifier functionality,
or test system power state transitions.

Signed-off-by: Kenneth J. Miller <[email protected]>

This property allows defining one or more power-states phandles in which
a peripheral loses its configuration, and must be reinitialized.

States below and including S2RAM are inherently assumed to require
reinit, this property is intended to cover the exceptions outside
of this common use case.

It is intended to assist drivers in preventing the SoC from entering
these power states during critical code sections, as well as indicate
to power management services when a peripheral needs reinitialization.

Signed-off-by: Kenneth J. Miller <[email protected]>

Add general purpose of and example use-case of the reinit-power-states
property added in this commit series.

Signed-off-by: Kenneth J. Miller <[email protected]>

Add helper macros for building a pm_state_info array from a device's
reinit-power-states.

These macros are intended to assist drivers in and around device
reinitializiation.

Signed-off-by: Kenneth J. Miller <[email protected]>

Refactor to prevent code duplication in the driver reinitialization
functionality following this commit.

Move HAL include statement from driver source to header to make header
self-contained.

Signed-off-by: Kenneth J. Miller <[email protected]>

The added reinitialization feature helps PM logic restore bus
functionality when clock context is lost in certain low-power modes.

Signed-off-by: Kenneth J. Miller <[email protected]>

Enable STOP2 reinitialization for affected USART and SPI peripheral
instances, as these will otherwise be INOP when the SoC returns from
STOP2 low-power mode.

Signed-off-by: Kenneth J. Miller <[email protected]>