kernel - Refactor the TSC MP synchronization test

kernel - Refactor the TSC MP synchronization test

* Refactor the TSC MP synchronization test.  Do not use cpusync.
  Using cpusync results in O(N x N) worth of overhead instead of
  O(N) worth of overhead.

  Instead, have the per-cpu threads run the test simultaneously using
  each other's data.

* We synchronize to the last TSC element that was saved on each cpu.
  This probably needs a bit of work to ensure determinism, but at
  the moment its good in that it synchronizes all cores off of a
  single cache mastership change, instead of having them all compete
  for cache mastership.

* Probably needs some fine tuning, at the moment I allow a slop of
  10uS which is almost certainly too much.  Note, however, that
  SMP interactions can create ~1uS latencies on particular memory
  accesses.

* Solves serious issues with the old test on 64 cpu threads.
  These issues may also have been related to the ipiq fifo size
  being too small.