From: Tom Rini <trini@kernel.crashing.org>

When I was updating ppc/boot/simple/relocate.S to work on PPC_PREP systems, I
in advertantly broke 4xx systems.  On classic PPC, the first three
instructions are nops, of which the first two can be overwritten.  This is
not true of 4xx (or 8xx, but that's not working right now anyhow).  The
following is needed to fix this.