iommu/arm-smmu: Get rid of weird "atomic" write

The smmu_write_atomic_lq oddity made some sense when the context
format was effectively tied to CONFIG_64BIT, but these days it's
simpler to just pick an explicit access size based on the format
for the one-and-a-half times we actually care.

Change-Id: I5b4ca8162c801aa320576ff3d31bb20acca9b1f8
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Git-repo: 61005762
Git-commit: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


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