Fix the build dependency between powernow-k{7,8} and acpi/processor.o by
adding a CONFIG_X86_POWERNOW_K{7,8}_ACPI bool, just like SPEEDSTEP_CENTRINO
does it. See http://forums.gentoo.org/viewtopic.php?t=186887 for a
bugreport.
Signed-off-by: Dominik Brodowski <linux@brodo.de>
Signed-off-by: Dave Jones <davej@redhat.com>