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/data.c b/data.c
index 588c87e..dd2e3d3 100644
--- a/data.c
+++ b/data.c
@@ -247,7 +247,7 @@
 
 struct data data_append_cell(struct data d, cell_t word)
 {
-	cell_t beword = cpu_to_be32(word);
+	cell_t beword = cpu_to_fdt32(word);
 
 	return data_append_data(d, &beword, sizeof(beword));
 }
@@ -256,15 +256,15 @@
 {
 	struct fdt_reserve_entry bere;
 
-	bere.address = cpu_to_be64(re->address);
-	bere.size = cpu_to_be64(re->size);
+	bere.address = cpu_to_fdt64(re->address);
+	bere.size = cpu_to_fdt64(re->size);
 
 	return data_append_data(d, &bere, sizeof(bere));
 }
 
 struct data data_append_addr(struct data d, uint64_t addr)
 {
-	uint64_t beaddr = cpu_to_be64(addr);
+	uint64_t beaddr = cpu_to_fdt64(addr);
 
 	return data_append_data(d, &beaddr, sizeof(beaddr));
 }