iommu/core: Add fault reporting mechanism

Add iommu fault report mechanism to the IOMMU API, so implementations
could report about mmu faults (translation errors, hardware errors,
etc..).

Fault reports can be used in several ways:
- mere logging
- reset the device that accessed the faulting address (may be necessary
  in case the device is a remote processor for example)
- implement dynamic PTE/TLB loading

A dedicated iommu_set_fault_handler() API has been added to allow
users, who are interested to receive such reports, to provide
their handler.

Change-Id: Id049671b7a0df27476c3cad451c2505e9b260ab6
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>