dmaengine: dw-axi-dmac: simplify descriptor management

dmaengine: dw-axi-dmac: simplify descriptor management

Simplify and refactor the descriptor management by removing the redundant
Linked List Item (LLI) queue control logic from the AxiDMA driver.
The descriptor is split into virtual descriptor and hardware LLI so that
only hardware LLI memories are allocated from the DMA memory pool.

Up to 64 descriptors can be allocated within a PAGE_SIZE compare to 16
descriptors in previous version. This solves the problem where an
ALSA driver expects more than 16 DMA descriptors to run.

Signed-off-by: Sia Jee Heng <jee.heng.sia@intel.com>
Tested-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Link: https://lore.kernel.org/r/20210125013255.25799-3-jee.heng.sia@intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>