Fix printf errors under -DDEBUG

Fix printf format-string/arg mismatches under -DDEBUG.

These warnings occur with DEBUG defined for a platform using
cpu/mpc85xx.  Users of other architectures can unearth similar
problems by adding the line "CFLAGS += -DDEBUG=1" in config.mk right
after "CFLAGS += $(call cc-option,-fno-stack-protector)".

Signed-off-by: Andrew Klossner <andrew@cesa.opbu.xerox.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>
diff --git a/common/image.c b/common/image.c
index f7e8606..d7fcd1d 100644
--- a/common/image.c
+++ b/common/image.c
@@ -1563,7 +1563,7 @@
 	*of_flat_tree = fdt_blob;
 	*of_size = be32_to_cpu (fdt_totalsize (fdt_blob));
 	debug ("   of_flat_tree at 0x%08lx size 0x%08lx\n",
-			*of_flat_tree, *of_size);
+			(ulong)*of_flat_tree, *of_size);
 
 	return 0;