[PATCH] ppc32: Workaround a cache flush issue on sleep

We are experiencing a problem when flushing the CPU caches before sleep
on some laptop models using the 750FX CPU rev 1.X. While I haven't been
able to figure out a proper explanation for what's going on, I do have a
workaround that seem to work reliably and allows those machine to sleep
and wakeup properly again.

I'll re-update that code if/when I ever find exactly what is happening
with those CPU revisions.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>