drm/bridge: tc358767: do no fail on hi-res displays

Do not fail data rates higher than 2.7 and more than 2 lanes.
Try to fall back to 2.7Gbps and 2 lanes.

Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Andrey Gusakov <andrey.gusakov@cogentembedded.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1510073785-16108-2-git-send-email-andrey.gusakov@cogentembedded.com