iommu/arm-smmu: Implement the unmap_pages() IOMMU driver callback

iommu/arm-smmu: Implement the unmap_pages() IOMMU driver callback

Implement the unmap_pages() callback for the ARM SMMU driver
to allow calls from iommu_unmap to unmap multiple pages of
the same size in one call. Also, remove the unmap() callback
for the SMMU driver, as it will no longer be used.

Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Georgi Djakov <quic_c_gdjako@quicinc.com>
Link: https://lore.kernel.org/r/1623850736-389584-15-git-send-email-quic_c_gdjako@quicinc.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>