[POWERPC] Use embedded dtc in kernel builds

This patch alters the kernel makefiles to build dtc from the sources
embedded in the previous patch.  It also changes the
arch/powerpc/boot/wrapper script to use the embedded dtc, rather than
expecting a copy of dtc already installed on the system.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/boot/wrapper b/arch/powerpc/boot/wrapper
index a591ced..f961cde 100755
--- a/arch/powerpc/boot/wrapper
+++ b/arch/powerpc/boot/wrapper
@@ -124,7 +124,7 @@
     if [ -z "$dtb" ]; then
 	dtb="$platform.dtb"
     fi
-    dtc -O dtb -o "$dtb" -b 0 -V 16 "$dts"
+    $object/dtc -O dtb -o "$dtb" -b 0 "$dts"
 fi
 
 if [ -z "$kernel" ]; then