iommu-updates-v3.13

This time the updates contain:

* Tracepoints for certain IOMMU-API functions to make
  their use easier to debug
* A tracepoint for IOMMU page faults to make it easier
  to get them in user space
* Updates and fixes for the new ARM SMMU driver after
  the first hardware showed up
* Various other fixes and cleanups in other IOMMU drivers