ppc: Move cpu/$CPU to arch/ppc/cpu/$CPU

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/board/mbx8xx/u-boot.lds b/board/mbx8xx/u-boot.lds
index dc3e580..3572f1a 100644
--- a/board/mbx8xx/u-boot.lds
+++ b/board/mbx8xx/u-boot.lds
@@ -52,7 +52,7 @@
   .plt : { *(.plt) }
   .text      :
   {
-    cpu/mpc8xx/start.o	(.text)
+    arch/ppc/cpu/mpc8xx/start.o	(.text)
 
     *(.text)
     *(.got1)