flounder: audio: Revise TFA configuration method

Can't guarantee I2S signal in previous way.
Enlarge stop_threshold for spk to avoid I2S drain in unexpected cases.
Also Avoid I2S turned off when selecting a new device.

Bug: 17490341

Change-Id: I322076c7643cacf6e8878ce454dea5a0a0f93309
Signed-off-by: wesley_wang <wesley_wang@htc.com>
1 file changed