common: Move device-tree setup functions to fdt_support.h

These functions relate to setting up the device tree for booting the OS.
The fdt_support.h header file supports similar functions, so move these
there.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/freescale/mpc8323erdb/mpc8323erdb.c b/board/freescale/mpc8323erdb/mpc8323erdb.c
index 6c47cb2..e513d0b 100644
--- a/board/freescale/mpc8323erdb/mpc8323erdb.c
+++ b/board/freescale/mpc8323erdb/mpc8323erdb.c
@@ -12,6 +12,7 @@
 #include <common.h>
 #include <eeprom.h>
 #include <env.h>
+#include <fdt_support.h>
 #include <init.h>
 #include <ioports.h>
 #include <mpc83xx.h>