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/amcc/taishan/taishan.c b/board/amcc/taishan/taishan.c
index cac7a78..2957a77 100644
--- a/board/amcc/taishan/taishan.c
+++ b/board/amcc/taishan/taishan.c
@@ -26,7 +26,7 @@
 #include <common.h>
 #include <asm/processor.h>
 #include <spd_sdram.h>
-#include <ppc4xx_enet.h>
+#include <asm/ppc4xx-emac.h>
 #include <netdev.h>
 
 #ifdef CONFIG_SYS_INIT_SHOW_RESET_REG