drm/amd/display: access ABM from stream resource.

[Why]
Since ABM resource is mapped to stream res, all the ABM access should
via stream res.

[How]
Get ABM instance from stream res instead of resource pool.

Signed-off-by: Yongqiang Sun <yongqiang.sun@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>