ppc4xx: Move ppc4xx headers to powerpc include directory

This patch moves some ppc4xx related headers from the common include
directory (include/) to the powerpc specific one
(arch/powerpc/include/asm/). This way to common include directory is not
so cluttered with files.

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/board/jse/jse.c b/board/jse/jse.c
index fb39c84..f5c52c9 100644
--- a/board/jse/jse.c
+++ b/board/jse/jse.c
@@ -19,7 +19,7 @@
  */
 
 # include  <common.h>
-# include  <ppc4xx.h>
+# include  <asm/ppc4xx.h>
 # include  <asm/processor.h>
 # include  <asm/io.h>
 # include  "jse_priv.h"