flash_ec: add nefario for support

BUG=b:63408169
BRANCH=none
TEST=utils/flash_ec --board=nefario

Change-Id: Ic13d6257a548d6c759542f3e8e679b0ce2b4de51
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Reviewed-on: https://chromium-review.googlesource.com/578694
Reviewed-by: Philip Chen <philipchen@chromium.org>
1 file changed