Replace "#include <asm-$ARCH/$FILE>" with "#include <asm/$FILE>"

The appropriate include/asm-$ARCH directory should already by symlinked
to include/asm so using the whole "asm-$ARCH" path is unnecessary.

This change should also allow us to move the include/asm-$ARCH
directories into their appropriate lib/$ARCH/ directories.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/board/esd/du440/init.S b/board/esd/du440/init.S
index 3cac6b1..afcf9c4 100644
--- a/board/esd/du440/init.S
+++ b/board/esd/du440/init.S
@@ -22,7 +22,7 @@
  */
 
 #include <ppc_asm.tmpl>
-#include <asm-ppc/mmu.h>
+#include <asm/mmu.h>
 #include <config.h>
 
 /*