dmaengine: Add Arm DMA-350 driver

Add an initial driver for the Arm Corelink DMA-350 controller, to
support basic mem-to-mem async_tx. The design here leaves room for more
fun things like peripheral support and scatter-gather chaining to come
in future.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/6d7d8efefa935d34977b59a74797ab377528db94.1741780808.git.robin.murphy@arm.com


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