servo_micro: Add UART baudrate controls

flash_ec script sets the UART baudrate. Add them for backward-
compatible, though we can't change their values.

BUG=b:37513705
TEST=dut-control ec_uart_baudrate:115200 ec_uart_baudrate

Change-Id: I4bc56455c0a98627363500a412e20c8dae5e4381
Reviewed-on: https://chromium-review.googlesource.com/726780
Commit-Ready: Wai-Hong Tam <waihong@google.com>
Tested-by: Wai-Hong Tam <waihong@google.com>
Reviewed-by: Nick Sanders <nsanders@chromium.org>
1 file changed