powerpc/ps3: Do not adjust the wrapper load address

Commit c55aef0e "powerpc/boot: Change the load address for the wrapper
to fit the kernel" adjusted the laod address if the uncompressed kernel
was too large.  Ps3 does not compress the kernel and uses a different
linker script, so do not adjust the load address in that case.

fixes this build error:

powerpc64-linux-ld: section .text loaded at [0000000000e00000,0000000000e0721b] overlaps section .kernel:dtb loaded at [0000000000e00000,0000000000e0066f]

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>