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/drivers/mtd/nand/ndfc.c b/drivers/mtd/nand/ndfc.c
index 0dd6789..3ca13a9 100644
--- a/drivers/mtd/nand/ndfc.c
+++ b/drivers/mtd/nand/ndfc.c
@@ -35,7 +35,7 @@
 #include <linux/mtd/nand_ecc.h>
 #include <asm/processor.h>
 #include <asm/io.h>
-#include <ppc4xx.h>
+#include <asm/ppc4xx.h>
 
 /*
  * We need to store the info, which chip-select (CS) is used for the