[CPUFREQ] Report the number of processors in PowerNow-k8 correctly

The PowerNow! driver for Opteron reports the number of cores
in the system, but claims to report the number of processors.
Fix this minor cosmetic bug.

Signed-off-by: Bhavana Nagendra <bhavana.nagendra@amd.com>
Acked-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>