[why] As DP features expands, we have encountered many situations where we must configure a different DPCD lane setting from hw lane settings we output. The change is to decouple hw lane settings from dpcd lane settings to provide flexibility to configure dpcd and hw individually. Reviewed-by: Jun Lei <Jun.Lei@amd.com> Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com> Signed-off-by: Wenjing Liu <wenjing.liu@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>