Two RAS related fixes:
- Shut down the per CPU thermal throttling poll work properly when a CPU
goes offline. The missing shutdown caused the poll work to be migrated
to a unbound worker which triggered warnings about the usage of
smp_processor_id() in preemptible context
- Fix the PPIN feature initialization which missed to enable the
functionality when PPIN_CTL was enabled but the MSR locked against
updates.