Fixes a case where we were not correctly acking the base cascade controller
on PPC4xx.  Patch from Pavel Bartusek <pba@sysgo.com>
Signed-off-by: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>