Add ctrl_s and arb_key controls to hdctools

Add ctrl+s so that faft tests can trigger setting vendor data in
depthcharge. Also add a key_press control so that a faft test can type
arbitray text in vendor data.

Also remove the d_key control, it does not apper to be used anywhere and
can be done with the new arb_key control.

BUG=b:129846461
TEST=Ran 'dut-control arb_key_config:d arb_key:tab' and got expected
     output on dut

Change-Id: Id42550af431e0cf33730cbe45713841d4ba747b5
Reviewed-on: https://chromium-review.googlesource.com/1550660
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Mathew King <mathewk@chromium.org>
Reviewed-by: Ruben Rodriguez Buchillon <coconutruben@chromium.org>
4 files changed