The only difference between scripts/dtc/libfdt/fdt_rw.c and
lib/libfdt/fdt_rw.c is fdt_remove_unused_strings().
It is only used by fdtgrep, so we do not need to compile it for U-Boot
image. Move it to tools/libfdt/fdw_rw.c so that lib/libfdt/fdt_rw.c
can be a wrapper of scripts/dtc/libfdt/fdt_rw.c.
Change-Id: I6e2578d4bfdf75438d3aa1cb51f270f34527d37d
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>