dtc: Use the same endian-conversion functions as libfdt

Currently both libfdt and dtc define a set of endian conversion macros
for accessing the device tree blob which is always big-endian.  libfdt
uses names like cpu_to_fdt32() and dtc uses names like cpu_to_be32 (as
the Linux kernel).  This patch switches dtc over to using the libfdt
macros (including libfdt_env.h to supply them).  This has a couple of
small advantages:
	- Removes some code duplication
	- Will make conversion a bit easier if we ever need to produce
          little-endian device tree blobs.
	- dtc no longer needs to pull in netinet/in.h simply for the
          ntohs() and ntohl() functions

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/treesource.c b/treesource.c
index 468d6b1..c32e818 100644
--- a/treesource.c
+++ b/treesource.c
@@ -147,7 +147,7 @@
 			m = m->next;
 		}
 
-		fprintf(f, "0x%x", be32_to_cpu(*cp++));
+		fprintf(f, "0x%x", fdt32_to_cpu(*cp++));
 		if ((void *)cp >= propend)
 			break;
 		fprintf(f, " ");