servo: pull ftdii2c commands into servod drv structure

This CL removes the special casing from ftdii2c controls in servod
by creating a drv for them & a config file.

This reduces code complexity in dut-control & servo_server, and reduces the
number of exposed rpcs. Lastly, these controls are only relevant for
servo v2. This only includes them in the servo v2 scenario. Lastly, it
doesn't crash the servod instance if an error occurs.

BUG=chromium:869335
TEST=manual testing servo v2
dut-control ftdii2c_cmd:close
dut-control ftdii2c_cmd:init
dut-control ftdii2c_cmd:open
no errors reported

Change-Id: I01548a5ebb92150a8cf0ca1773412e5663b42508
Signed-off-by: Ruben Rodriguez Buchillon <coconutruben@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1156425
Tested-by: Matthew Blecker <matthewb@chromium.org>
Reviewed-by: Matthew Blecker <matthewb@chromium.org>
Reviewed-by: Todd Broch <tbroch@chromium.org>
6 files changed