fflash: Add integration test

BUG=None
TEST=ninja -v
TEST=bin/fflash ${dut_host}
TEST=bin/integration-test ${dut_host}

Change-Id: I342bcffb81594ca6485f734402c67deebda8cc6e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/3947885
Commit-Queue: Li-Yu Yu <aaronyu@google.com>
Tested-by: Li-Yu Yu <aaronyu@google.com>
Reviewed-by: Terry Cheong <htcheong@chromium.org>
3 files changed