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/esd/pci405/writeibm.S b/board/esd/pci405/writeibm.S
index 4e319c1..5925bc6 100644
--- a/board/esd/pci405/writeibm.S
+++ b/board/esd/pci405/writeibm.S
@@ -41,7 +41,7 @@
 /*	Bank 6 - not used */
 /*	Bank 7 - FPGA registers */
 /*----------------------------------------------------------------------------- */
-#include <ppc4xx.h>
+#include <asm/ppc4xx.h>
 
 #include <ppc_asm.tmpl>
 #include <ppc_defs.h>