iommu: Change iommu driver to call detach_device_to_domain trace event

Change iommu driver to call detach_device_to_domain trace event. This
iommu_device class event can be enabled to trigger when devices are detached
from a domain. Trace information includes device name.

Testing:
Added trace calls to iommu_prepare_identity_map() for testing some of the
conditions that are hard to trigger. Here is the trace from the testing:

       swapper/0-1     [003] ....     1.854102: detach_device_from_domain: IOMMU: device=0000:00:02.0

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 74c371c..b630754 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -702,6 +702,7 @@
 		return;
 
 	domain->ops->detach_dev(domain, dev);
+	trace_detach_device_from_domain(dev);
 }
 EXPORT_SYMBOL_GPL(iommu_detach_device);