Some time ago, a copies of the upstream dtc and libfdt sources were
included in the kernel tree to avoid having these as external
dependencies for building the kernel.  Since then development on the
upstream dtc and libfdt has continued.  This updates the in-kernel
versions to match the recently released upstream dtc version 1.2.0.
This includes a number of bugfixes, many cleanups and a few new
features.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

This incorporates libfdt (from the source embedded in an earlier
commit) into the wrapper.a library used by the bootwrapper.  This
includes adding a libfdt_env.h file, which the libfdt sources need in
order to integrate into the bootwrapper environment, and a
libfdt-wrapper.c which provides glue to connect the bootwrapper's
abstract device tree callbacks to the libfdt functions.

In addition, this changes the various wrapper and platform files to
use libfdt functions instead of the older flatdevtree.c library.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>