iommu/arm-smmu-v3: Add types for each level of the CD table

As well as indexing helpers arm_smmu_cdtab_l1/2_idx().

Remove CTXDESC_L1_DESC_DWORDS and CTXDESC_CD_DWORDS replacing them all
with type specific calculations.

Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/7-v4-6416877274e1+1af-smmuv3_tidy_jgg@nvidia.com


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