ASoC: samsung: dma: Implement audio pause/resume callback operations

ASoC: samsung: dma: Implement audio pause/resume callback operations

When the dma operations get called from audio platform driver, and
users want to pause or resume the audio pcm stream when playback music,
there should be the related pause and release callback operations for
such requirements. This patch just implements the audio pause/resume
callback operations by simply call the corresponding functions from
the dma engine subsystem.

Change-Id: Ifed8d2acf1cbc09f1bd5d37151dcf74255b20da0
Signed-off-by: Huang Chao <chao7.huang@samsung.com>