iommu: Add iommu_error class event to iommu trace

iommu_error class event can be enabled to trigger when an iommu
error occurs. This trace event is intended to be called to report the
error information. Trace information includes driver name, device name,
iova, and flags.

iommu_error:io_page_fault

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>