By standard (ACPI 5 chapter 8.4 Declaring Processors) Processors can be
implemented in 2 distinct ways:
- Through a Processor object type (which provides P_BLK)
- Through a Device object type
Right now FreeBSD driver only supports the former, while AMD Epyc/Poweredge so
far both implement the latter. Add the missing support.
Because P_BLK is not defined in the device object case, C-states entering must
be completely controlled via _CST methods rather than P_LVL2/3.
Submitted by: Attilio