mixer.h already contains some channel position definitions.
To be more consistent over all systems, better to follow the same
order for the new channel map, too. But since UNKNOWN channel must be
zero but the definition in mixer.h contains -1 as UNKNOWN, simply
shift the value with 1.
If the conversion is required between SND_CHMAP and SND_MIXER_SCHN,
just increment/decrement 1. Eventually I'll provide helper functions
for that...
Signed-off-by: Takashi Iwai <tiwai@suse.de>
