drm/amd/display: add two lane settings training options

[why]
option 1: disallow different lanes to have different lane settings
option 2: dpcd lane settings will always use the same hw lane settings
even if it doesn't match requested lane adjust

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>