drm/bridge: tc358767: cleanup aux_link_setup

The driver sets up AUX link at probe time, but, for some reason, also
sets the main link's number of lanes using tc->link.base.num_lanes. This
is not needed nor correct, as the number of lanes has not been decided
yet. The number of lanes will be set later during main link setup.

Modify aux_link_setup so that it does not use tc->link, and thus makes
aux setup independent of the link probing.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528082747.3631-7-tomi.valkeinen@ti.com