servod: support parity on servo_micro

Add uart_parity controls and drv support
for servo_micro.

BUG=b:37513705
TEST=set parity on servo micro

Change-Id: I02fae2bc587d84e2cc0aad36cb2c8479d5b1b69b
Reviewed-on: https://chromium-review.googlesource.com/564306
Commit-Ready: Nick Sanders <nsanders@chromium.org>
Tested-by: Nick Sanders <nsanders@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
3 files changed