dmaengine: ptdma: Initial driver for the AMD PTDMA

Add support for AMD PTDMA controller. It performs high-bandwidth
memory to memory and IO copy operation. Device commands are managed
via a circular queue of 'descriptors', each of which specifies source
and destination addresses for copying a single buffer of data.

Signed-off-by: Sanjay R Mehta <sanju.mehta@amd.com>
Link: https://lore.kernel.org/r/1629208559-51964-2-git-send-email-Sanju.Mehta@amd.com


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