Simplified some documentation, removing inconsistencies and making
it easier to understand by separating PM infrastructure areas and
soc specific components that implement the hooks.
Removed the DEVICE_SUSPEND_ONLY policy as it is redundant and
causes high complexity in the flow. It is also not practical
to use it because it was meant to be used without doing CPU or SOC
low power state operations. This means it would do device PM
operations in the ISR of the system timer used by the scheduler.
This can disrupt the scheduler time.
Added a check of a flag around the notification sent from the ISR
of the wake event and created APIs to set/clear it. This will
allow disabling the notification when not needed from
_sys_soc_suspend().
Jira: ZEP-972
Change-Id: Id7aa7d2683384eabed518d4efac446ecc84c3498
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
c4c0ed414b