Audio: add mixer control api to adjust volume & mute [1/2]

PD#SWPL-131125

Problem:
there is no audio server, need use mixer control to control volume/mute.

Solution:
add mixer control api.
1)volume kcontrol: "TDMOUT_B Software Gain"
2)mute:
hdmi output kcontrol: "Audio hdmi-out mute"
headphone output kcontrol: "DAC Digital Playback Volume"

3)test usage:
set volume: test_audiosetting volume x (x is vol value, 0~100)
get volume: test_audiosetting volume
set mute  : test_audiosetting mute port x
(port:hdmi or hp, x is mute:1 or unmute:0)
get mute  : test_audiosetting mute port (port:hdmi or hp)

Verify:
S805C1A_2k yocto.

Change-Id: I5eb9a1b78c1551a2af06a6615ff2ff1567849b6c
Signed-off-by: wei.wang1 <wei.wang1@amlogic.com>
7 files changed
tree: 1c7f6d571025160ce309bfda736815170cdf683e
  1. include/
  2. src/
  3. Makefile