Flattening dc transfer functions in the following manner:
transfer_func > core_transfer_func > dc_transfer_func

References to deleted structs are updated as needed.
Signed-off-by: NLeo (Sunpeng) Li <sunpeng.li@amd.com>
Reviewed-by: NTony Cheng <Tony.Cheng@amd.com>
Acked-by: NHarry Wentland <Harry.Wentland@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>