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/arch/powerpc/cpu/ppc4xx/miiphy.c b/arch/powerpc/cpu/ppc4xx/miiphy.c
index 4fec126..3b28122 100644
--- a/arch/powerpc/cpu/ppc4xx/miiphy.c
+++ b/arch/powerpc/cpu/ppc4xx/miiphy.c
@@ -41,8 +41,8 @@
 #include <asm/io.h>
 #include <ppc_asm.tmpl>
 #include <commproc.h>
-#include <ppc4xx_enet.h>
-#include <405_mal.h>
+#include <asm/ppc4xx-emac.h>
+#include <asm/ppc4xx-mal.h>
 #include <miiphy.h>
 
 #if !defined(CONFIG_PHY_CLK_FREQ)