iommu: Change iommu driver to call map trace event

Change iommu driver to call map trace event. This iommu_map_unmap class event
can be enabled to trigger when iommu map iommu ops is called. Trace information
includes iova, physical address (map event only), and size.

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: map: IOMMU: iova=0x00000000cb800000 paddr=0x00000000cf9fffff size=0x400
Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

drivers/iommu/iommu.c

@@ -842,6 +842,8 @@ int iommu_map(struct iommu_domain *domain, unsigned long iova,
 	/* unroll mapping in case something went wrong */
 	if (ret)
 		iommu_unmap(domain, orig_iova, orig_size - size);
+	else
+		trace_map(iova, paddr, size);
 
 	return ret;
 }