channel 1: SYSMEM<->ACP
channel 2: ACP<->I2S
Instead of waiting on period interrupt of ch 2 and then starting
dma on ch1, we make ch1 dma as circular.
This removes dependency of period granularity on hw pointer.
Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com> Reviewed-by: Daniel Kurtz <djkurtz@chromium.org> Tested-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Mark Brown <broonie@kernel.org>