iommu-common: Fix error code used in iommu_tbl_range_{alloc,free}().

The value returned from iommu_tbl_range_alloc() (and the one passed
in as a fourth argument to iommu_tbl_range_free) is not a DMA address,
it is rather an index into the IOMMU page table.

Therefore using DMA_ERROR_CODE is not appropriate.

Use a more type matching error code define, IOMMU_ERROR_CODE, and
update all users of this interface.

Reported-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>