Add the binaries for flashrom and libfdt needed to flash some
Chromebok models such as the rk3399-gru-kevin using a Servo-Micro
board.  These were built within the Chrome OS chroot.

If we need to keep using flashrom and libfdt, we should consider
existing Debian packages and adding any Chrome OS specific patches if
needed rather than tracking binaries directly.

Signed-off-by: Guillaume Tucker <guillaume.tucker@collabora.com>