iommu/sprd: Drop IOVA cookie management

The core code bakes its own cookies now.

Acked-by: Chunyan Zhang <zhang.lyra@gmail.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/4e7fc6e523cb4b63fb13f5be10041eb24c0dcb1e.1628682048.git.robin.murphy@arm.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>