CRAS: iodev - Mute input buffer before dsp or effects

This is to fix a bug when system mic mute is set
non-zero data still passes to stream when the AEC
effects is used.

- Mute input HW buffer before dsp(including other
processing is applied).
- Mute buffer again when copies to input stream.

BUG=chromium:1203163, b:189291363
TEST=Mute mic on UI settings. Execute
cras_test_client -C /tmp/1 --effects aec
verify nothing was recorded.

Change-Id: I69d0946f2654a7af45ddff960252352fa152ef02
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/adhd/+/2919253
Tested-by: Hsinyu Chao <hychao@chromium.org>
Commit-Queue: Hsinyu Chao <hychao@chromium.org>
Reviewed-by: Cheng-Yi Chiang <cychiang@chromium.org>
(cherry picked from commit c7f19aa296b8384d309e6426fecdf35359a4e956)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/adhd/+/2921791
Reviewed-by: Hsinyu Chao <hychao@chromium.org>
3 files changed