drm/nouveau: Implement intersect/compatible functions

Implemented a new intersect and compatible callback function
fetching the start offset from struct ttm_resource.

Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220820073304.178444-5-Arunpravin.PaneerSelvam@amd.com