Doxygen: Added PMU documentation for CM85 and extended for CM55
Doxygen: Added PMU documentation for CM85 and extended for CM55

ARM-software/CMSIS_5,ARM-software/CMSIS_5,ARM-software/CMSIS_5,JonatanAntoni/CMSIS_5,JonatanAntoni/CMSIS_5,JonatanAntoni/CMSIS_5,ARM-software/CMSIS_5,JonatanAntoni/CMSIS_5,JonatanAntoni/CMSIS_5,ARM-software/CMSIS_5,ARM-software/CMSIS_5,JonatanAntoni/CMSIS_5