dmaengine: idxd: add module parameter to force disable of SVA

dmaengine: idxd: add module parameter to force disable of SVA

Add a module parameter that overrides the SVA feature enabling. This keeps
the driver in legacy mode even when intel_iommu=sm_on is set. In this mode,
the descriptor fields must be programmed with dma_addr_t from the Linux DMA
API for source, destination, and completion descriptors.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/161134110457.4005461.13171197785259115852.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>