AMD recently errata'd the definition of the PSB/PST for recent Athlon 64 and Opteron parts.  The errata
allows for a second, identical PST for those parts.
The current powernow-k8 driver will not work in PST/PSB mode on those parts because it requires 
there be 1 and only 1 PST.

From: Mark Langsdorf
Signed-off-by: Dave Jones <davej@redhat.com>