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/mpc8349itx/mpc8349itx.c b/board/freescale/mpc8349itx/mpc8349itx.c
index 81b3f00..a2e284f 100644
--- a/board/freescale/mpc8349itx/mpc8349itx.c
+++ b/board/freescale/mpc8349itx/mpc8349itx.c
@@ -4,6 +4,7 @@
  */
 
 #include <common.h>
+#include <fdt_support.h>
 #include <ioports.h>
 #include <mpc83xx.h>
 #include <i2c.h>