This patch adds the PREEMPT_BKL config option for PPC64, shamelessly
stolen from the i386 version.  I have this turned on in the kernel on
my desktop G5 and it seems to be just fine.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>