[CPUFREQ] Powernow-k8: Update to support the latest Turion processors

The latest series of Turion X2 processors have a new XFAM
model.  Add support for them to powernow-k8.h.

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