drm/bridge: tc358767: Use DP nomenclature

The DP specification uses the term "default framing" instead of "non-
enhanced framing".

Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191021143437.1477719-11-thierry.reding@gmail.com