lib: add fdt_empty_tree.c

CONFIG_LIBFDT support does not include fdt_empty_tree.c which is
needed by arm64 EFI stub. Add it to libfdt_files.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
(cherry picked from commit adaf5687846c25613d58c0a2f5d9e024547cdbec)
Signed-off-by: Mark Brown <broonie@linaro.org>
2 files changed