Add support for FruitPie debug interface

Allow to flash the STM32F072 over the built-in FT230X chip
and use the serial port.

BUG=none
TEST=launch servod, flash_ec and serial console

Change-Id: I7653ab6875c72889b9aa7bc0b02d868d9c55a58d
Reviewed-on: https://chromium-review.googlesource.com/191091
Reviewed-by: Todd Broch <tbroch@chromium.org>
Commit-Queue: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>
3 files changed