drm/bridge/analogix/anx6345: Don't link encoder until after connector registration

Another case of linking an encoder to a connector after the connector's
been registered. The proper place to do this is before connector
registration, so let's fix that.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219215326.2227596-12-lyude@redhat.com