dmaengine: sun4i: Add support for cyclic requests with dedicated DMA

Currently the cyclic transfers can be used only with normal DMAs. They
can be used by pcm_dmaengine module, which is required for implementing
sound with sun4i-hdmi encoder. This is so because the controller can
accept audio only from a dedicated DMA.

This patch enables them, following the existing style for the
scatter/gather type transfers.

Signed-off-by: Stefan Mavrodiev <stefan@olimex.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20200110141140.28527-2-stefan@olimex.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>