Implement new API functions for audio streaming

Implement new API functions for audio streaming

- Requirements:
The client library needs to provide new API for starting, sending,
stopping audio streaming feature. And also, the client library needs to
provide new API for getting audio format information.

- Contents:
To provide new API functions for audio streaming, this patch adds
implementation for these new functions. Through this patch, this module
has prepared to provide new API for audio streaming.

Change-Id: I88016a602f44c0325e7e58fc63c03872a8533f6d
Signed-off-by: Suyeon Hwang <stom.hwang@samsung.com>