dmaengine: dw-axi-dmac: support parallel memory <--> peripheral transfers

Added support for multiple DMA_MEM_TO_DEV, DMA_DEV_TO_MEM transfers in
parallel. This is required for peripherals using DMA for transmit and
receive operations at the same time. APB slot number needs to be
programmed in channel hardware handshaking interface

Signed-off-by: Pandith N <pandith.n@intel.com>
Tested-by: Pan Kris <kris.pan@intel.com>
Link: https://lore.kernel.org/r/20210802055454.15192-3-pandith.n@intel.com


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