hopefully 'better' fix for broken Intel Mercury/Neptune in
wait_8254_wraparound() ...

Rationale:

changing HZ to higher values (like 5k,10k or 20k) will hang machines using
wait_8254_wraparound() indefinitely, because a suboptimal workaround for
buggy Intel Mercury/Neptune chipsets is in place.

this was tested on several machines, unfortunately none with a broken Intel
Mercury/Neptune chipset, and it works fine with various HZ values ...
Signed-off-by: Herbert Pötzl <herbert@13thfloor.at>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>