audiofuntest: support setting range of frequency.

This CL adds config arguments 'min-frequency' and 'max-frequency' to
audiofuntest in order to let user define the range of frequency of the
generated tone.

BUG=none
TEST=manually test on the DUT.

Change-Id: Ieabf62dd232b542fbbf9f223845bce686ceb65b2
Reviewed-on: https://chromium-review.googlesource.com/1748769
Tested-by: Cheng Yueh <cyueh@chromium.org>
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Wei-Han Chen <stimim@chromium.org>
Reviewed-by: Yu-Hsuan Hsu <yuhsuan@chromium.org>
2 files changed