Includes reference to esp32 deep sleep sample code
to system power management documentation,
Signed-off-by: Glauber Maroto Ferreira <glauber.ferreira@espressif.com>
Device power management introduction was mentioning an APIs
that no longer exists and also using a wrong nomenclature for
device runtime pm.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Document the limitations of system power management when it comes to
transitions that are run from the idle thread.
Signed-off-by: Jordan Yates <jordan.yates@data61.csiro.au>
