Besides the prereqs requested to the remaining patch from v1 there's
yet one more thing to consider pulling in (RFC for now), and one
further custom change I'd like us to consider making (potentially
even going farther than presented here).

1: stop exposing platform acronyms
2: switch to using bool
3: add SnowRidge C-state table
4: enable interrupts before C1 on Xeons
5: squash stats update when not actually entering C-state

Jan