Until now new context would start as empty, then populated
with exsisting pipes + new. Now we start with duplication
of existing context and then add/delete from the context
pipes as needed.

This allows to do a per stream resource
population, start discarding dc_validation_set
and by this brings DC closer to to DRM.

v2: Add some fixes and rebase.
Signed-off-by: NAndrey Grodzovsky <Andrey.Grodzovsky@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>