This supports e500v1, e500v2, and e500mc. Tested only on e500v2, but the
performance counters are identical across all, with e500mc having some
additional events.
Relnotes: Yes
This also fixes asserts on removal of the module for the mpc74xx.
The PowerPC 970 processors have two different types of events: direct events
and indirect events. Thus far only direct events are supported. I included
some documentation in the driver on how indirect events work, but support is
for the future.
MFC after: 1 month
