Handle all DMA IOMMU group related dependencies before the
group is removed and we try to access it after free.

v2:
Move the actul handling function to TTM
Signed-off-by: NAndrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>