[PATCH] ppc32: Correct an instruction in the boot code

In the flush and invalidate bootcode on PPC4xx we were accidentally using
the wrong instruction.  Use cmplw, which reads from a register like we
want.

Signed-off-by: Tom Rini <trini@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>