Minor changes are required to get libfdt to build as part of qemu.
The patch below records modifications relative to upstream dtc-v1.2.0.

Index: libfdt_env.h
===================================================================
--- libfdt_env.h	(revision 230023)
+++ libfdt_env.h	(working copy)
@@ -4,10 +4,9 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>
-#include <endian.h>
-#include <byteswap.h>
+#include "bswap.h"
 
-#if __BYTE_ORDER == __BIG_ENDIAN
+#ifdef WORDS_BIGENDIAN
 #define fdt32_to_cpu(x)		(x)
 #define cpu_to_fdt32(x)		(x)
 #define fdt64_to_cpu(x)		(x)