drm/amd/display: remove surface validation against stream rect

Surface information is by default copied from old context in dc_commit_stream.
Thus unchange streams will not be affected. For new streams, we shouldn't
validate the new mode against the surface configuration of old_context.

Signed-off-by: Reza Amini <reza.amini@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>