iommu/io-pgtable: Remove map/unmap

With all users now calling {map,unmap}_pages, retire the redundant
single-page callbacks.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/a5a3cbf95c3279982e378cc43dad830322a59868.1668100209.git.robin.murphy@arm.com


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