dmaengine: Add Intel LGM SoC DMA support.

Add DMA controller driver for Lightning Mountain (LGM) family of SoCs.

The main function of the DMA controller is the transfer of data from/to any
peripheral to/from the memory. A memory to memory copy capability can also
be configured.

This ldma driver is used for configure the device and channnels for data
and control paths.

Signed-off-by: Amireddy Mallikarjuna reddy <mallikarjunax.reddy@linux.intel.com>
Link: https://lore.kernel.org/r/5fc54eb7ccfad4f8dd812b66b884054fc55cf050.1606905330.git.mallikarjunax.reddy@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>