ASoC: msm: qdsp6v2: Copy multiple frames per msm-pcm-q6 copy

Enable msm-pcm-q6 driver to copy and send multiple
frames on a single call to the copy function for
playback.

Change-Id: I70bb87ceeeef25dfd852c94d2315361f79ac8504
Signed-off-by: Ben Romberger <bromberg@codeaurora.org>