adpcm_dtk: Decode interleaved channels in parallel

Signed-off-by: James Almer <jamrial@gmail.com>
adpcm_dtk: Reindent after last commit

Signed-off-by: James Almer <jamrial@gmail.com>
adpcm_thp: Reindent

Signed-off-by: James Almer <jamrial@gmail.com>