iommu: Change iommu driver to call add_device_to_group trace event
Change iommu driver to call add_device_to_group trace event. This iommu_group
class event can be enabled to trigger when devices get added to an iommu group.
Trace information includes iommu group id and device name.
Testing:
The following is trace is generated when intel-iommu driver adds devices to
to iommu groups during boot-time during its initialization: