talk: On hwcodec disabling DMA interrupt is required during buflib move

Even though the DMA buffer itself does not move the ISR copies from a movable
buffer into the static commit buffer. To ensure this copying yields consistent
data it must not be interrupted by this ISR..

Also bump the commit buffer size to 2k, this should reduce the overhead
considerably because many clips are smaller than that (especially on
swcodec/speex).

Change-Id: I4e1ab83074f31fc91b51a58baa1df55ce659ac73
1 file changed