iommu/ipmmu-vmsa: Update to {map,unmap}_pages

Update map/unmap to the new multi-page interfaces, which is dead easy
since we just pass them through to io-pgtable anyway. Since these are
domain ops now, the domain is inherently valid (not to mention that
container_of() wouldn't return NULL anyway), so garbage-collect that
check in the process.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/ad859ccc24720d72f8eafd03817c1fc11255ddc1.1668100209.git.robin.murphy@arm.com


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