For functions returning nothing, there is no need to document
with @return, as Doxgen complains about "documented empty
return type of ...".
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
Reboot functionality has nothing to do with PM, so move it out to the
subsys/os folder.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>