iommu/dma: Prune redundant pgprot arguments

Somewhere amongst previous refactorings, the pgprot value in
__iommu_dma_alloc_noncontiguous() became entirely unused, and the one
used in iommu_dma_alloc_remap() can be computed locally rather than by
its one remaining caller. Clean 'em up.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/c2a81b72df59a71a13f8bad94f834e627c4c93dd.1717504749.git.robin.murphy@arm.com


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