ANDROID: sound: usb: Add vendor's hooking interface

In mobile, a co-processor can be used with USB audio to improve power
consumption.  To support this type of hardware, hooks need to be added
to the USB audio subsystem to be able to call into the hardware when
needed.

This interface can be support multiful USB audio devices.
It is depends on co-processor's F/W.

The main operation of the call-backs are:
- Initialize the co-processor by transmitting data when initializing.
- Change the co-processor setting value through the interface
function.
- Configure sampling rate
- pcm open/close
- other housekeeping

Bug: 156315379
Signed-off-by: Oh Eomji <eomji.oh@samsung.com>
Signed-off-by: JaeHun Jung <jh0801.jung@samsung.com>
[rework api to be a bit more self-contained and obvious - gregkh]
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I39061f6cc85be7bcae8db0e612fe58396bdedb24