audio: Add Kctrl to set DRC mode [2/3]

PD#SWPL-139729

Problem:
Actually the result of default mode is line,
for DVB product,it is must be set on RF mode

Solution:
1) kcontrol named "Audio Digital Mode";
2) test usage:
Set DRC mode: test_audiosetting drc "RF" ;
Get DRC mode: test_audiosetting drc;

Verify:
S805C1-BG201

Change-Id: I55bdf02eafef49010161dff19bece8377794f923
Signed-off-by: haiyang.ren <haiyang.ren@amlogic.com>
3 files changed
tree: 640a6e5dd03362c8e2aa813c68aa8773c715cb4e
  1. include/
  2. src/
  3. Makefile