iommu/io-pgtable: Remove TLBI_ON_MAP quirk

IO_PGTABLE_QUIRK_TLBI_ON_MAP is now fully superseded by the
core API's iotlb_sync_map callback.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/5abb80bba3a7c371d5ffb7e59c05586deddb9a91.1611764372.git.robin.murphy@arm.com
[will: Remove unused 'iop' local variable from arm_v7s_map()]
Signed-off-by: Will Deacon <will@kernel.org>