driver core: Add iommu_group tracking to struct device
driver core: Add iommu_group tracking to struct device

IOMMU groups allow IOMMU drivers to represent DMA visibility
and isolation of devices.  Multiple devices may be grouped
together for the purposes of DMA.  Placing a pointer on
struct device enable easy access for things like streaming
DMA programming and drivers like VFIO.

Signed-off-by: Alex Williamson <7469de9b95ba379e2656fa9677689657c47a7690@redhat.com>
Acked-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>
Acked-by: Benjamin Herrenschmidt <a7089bb6e7e92505d88aaff006cbdd60cc9120b6@kernel.crashing.org>
Signed-off-by: Joerg Roedel <ebd221a096cbc71dd9e1991db28795933c85f380@amd.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs