iommu: Remove iommu_fwspec ops

The ops in iommu_fwspec are only needed for the early configuration and
probe process, and by now are easy enough to derive on-demand in those
couple of places which need them, so remove the redundant stored copy.

Tested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/55c1410b2cd09531eab4f8e2f18f92a0faa0ea75.1719919669.git.robin.murphy@arm.com


Signed-off-by: Will Deacon <will@kernel.org>