cpufreq / powernow-k8: Fixup missing _PSS objects message

_PSS objects can also be missing if Cool'N'Quiet is disabled in the
BIOS. Add that to the FW_BUG message for the user to try before updating
her BIOS. Fix formatting while at it.

Acked-by: Mark Langsdorf <mark.langsdorf@amd.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>