BACKPORT: UPSTREAM: iommu/arm-smmu: Add pm_runtime/sleep ops

The smmu needs to be functional only when the respective
master's using it are active. The device_link feature
helps to track such functional dependencies, so that the
iommu gets powered when the master device enables itself
using pm_runtime. So by adapting the smmu driver for
runtime pm, above said dependency can be addressed.

This patch adds the pm runtime/sleep callbacks to the
driver and the corresponding bulk clock handling for all
the clocks needed by smmu.

Also, while we enable the runtime pm, add a pm sleep suspend
callback that pushes devices to low power state by turning
the clocks off in a system sleep.
Add corresponding clock enable path in resume callback as well.

This backport fixes the previously merged ff0fa3d2 ("FROMLIST:
iommu/arm-smmu: Add pm_runtime/sleep ops") to match the upstream result,
without having to revert a series of FROMLIST.

BUG=b:137202421
TEST=Run label_image in loop

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
[Thor: Rework to get clocks from device tree]
Signed-off-by: Thor Thayer <thor.thayer@linux.intel.com>
[vivek: rework for clock and pm ops]
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Thor Thayer <thor.thayer@linux.intel.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit dfa3261d319a2513314f3d88ab18871e5a8670af
https://github.com/ldts/qualcomm-lt-kernel/commits/chromiumos-4.14-iommu-mmap-gw-rebased-for-next

)
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Abhinav Asati <asatiabhi@codeaurora.org>
Change-Id: I7d9edebaf5638e832d59066ce51162cf3b57d06f
Signed-off-by: Vamsi Singamsetty <vamssi@codeaurora.org>