Revert "iommu/arm-smmu: Disable stalling faults for all endpoints"

This reverts commit 3714ce1d ("iommu/arm-smmu: Disable stalling
faults for all endpoints")

Msm drivers make use of the report_iommu_fault callback. Additionally,
stalling faults are supported on our hardware, and is useful for
debugging.

Change-Id: I52ce79acce0a356a9dc967da38d340268eacf4b1
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>