include: add includes includes to make fdt.h, of.h and state.h self contained ...

Otherwise compilation may fail with:

include/fdt.h:11:15: error: unknown type name 'uint64_t'
 static inline uint64_t fdt64_to_cpu(uint64_t x)

include/of.h:22:19: error: field 'list' has incomplete type
  struct list_head list;

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

of: remove unused libfdt ...

Now that we are completely independent of libfdt remove the unused
code.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

initial libfdt support ...

vanilla libfdt 1.3.0 from the dtc git:

git://git.jdl.com/software/dtc.git

Only small adjustments to compile with barebox

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>