Source Code Structure
The following code block shows the source code structure of the DMA
            engine.
    -- drivers
-- dma
-- dw-axi-dmac
   |-- Makefile
   |-- dw-axi-dmac-platform.c
   |-- dw-axi-dmac.h
-- dw-axi-dmac-starfive
   |-- Makefile
   |-- dw-axi-dmac-starfive-misc.c
   |-- starfive_dmaengine_memcpy.c
