i9500: audio: set better values for mixer_paths.xml

For a long time now users were switching from the stock mixer_paths.xml
to the one with these changes. After all of that, I think it's time to
check it out.

Change-Id: Id81303d8063a6f584b85271ecf13033a5fdc6d95
Merge pull request #1 from CarbonDev/kk

i9500: audio: set better values for mixer_paths.xml