The current status of main power supply monitoring. The
monitoring of the main power supply and its fan is always
enabled by those systems that support it. Systems which do
not support main power supply or fan monitoring report a
value of notSupported. The value ok is returned for those
systems that do support main power supply and fan monitoring,
and where the monitoring operation is reporting valid information (refer
to fanAndPsMainFanStatus for the current status of the system).
When main power supply and fan monitoring is failing, the value
notOk is returned.