drm/amdkfd: Add memory exception handling

This patch adds Peripheral Page Request (PPR) failure processing
and reporting.

Bad address or pointer to a system memory block with inappropriate
read/write permission cause such PPR failure during a user queue
processing. PPR request handling is done by IOMMU driver notifying
AMDKFD module on PPR failure.

The process triggering a PPR failure will be notified by
appropriate event or SIGTERM signal will be sent to it.

v3:
- Change all bool fields in struct kfd_memory_exception_failure to
  uint32_t

Signed-off-by: Alexey Skidanov <alexey.skidanov@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>