iommu/arm-smmu: Convert context bank registers to bitfields

Finish the final part of the job, once again updating some names to
match the current spec.

Change-Id: I405fa064194b5c90b13935fb37b36ba9e8ee35c0
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Git-commit: 620565a7
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


[isaacm@codeaurora.org: resolved merge conflicts/build time errors]
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>