This instrument will log serial traffic to a file. The idea is to
assist with debugging development boards, as otherwise there is a
chance that crash reports, for example, are lost when the device is
reset by WA.
It logs the pre-run and post-run traffic to preamble_serial.log and
postamble_serial.log , respectively, in the top-level output
directory. Serial logs for each workload are stored in the appropriate
workload directory as serial.log.
As we are tying up the serial port, we stop the logging when the
device is reset to allow board such as the Arm Juno to be reset via
the serial connection.
