Add additional defines describing the DMA registers
as well as adding some more documentation to those registers.
Signed-off-by: NMartin Sperl <kernel@martin.sperl.org>
Reviewed-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>