Audio: use LLI dma transfer for audio firmware download.

Audio: use LLI dma transfer for audio firmware download.

BZ: 25658

Currently firmware is downloaded through single block dma mode.
This causes sst driver to submit block by block.

Add support for LLI (Linked list item also known as multi block) DMA transfer
in which driver can submit multiple DMA descriptor and then initiated
DMA just in one trigger. This will use DMA engine's capability effectively
thus reducing the time consumed in downloading the audio firmware.

This patch implements memory to memory LLI transfer mechanism in DMA driver
and modifies the SST driver to use the LLI capability.

Change-Id: I1b0ce209eae7eb3ae7392dfb66a34d8388610e71
Signed-off-by: Namarta Kohli <namartax.kohli@intel.com>
Reviewed-on: http://android.intel.com:8080/40906
Reviewed-by: Gupta, ArvindX K <arvindx.k.gupta@intel.com>
Reviewed-by: Vinnakota, Lakshmi N <lakshmi.n.vinnakota@intel.com>
Reviewed-by: Hibare, PramodX <pramodx.hibare@intel.com>
Tested-by: Hibare, PramodX <pramodx.hibare@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>