drm/amd/display: Fix merging dynamic ODM+MPO configs on DCN32

[WHY&HOW?]
When merging ODM pipes that are using MPO, we must copy the stream_res
from the new top pipe to the bottom pipe so that the overlayed plane is
not pointing to the wrong stream assets.

Reviewed-by: Martin Leung <Martin.Leung@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Dillon Varone <Dillon.Varone@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>