drm/sun4i/sun4i_hdmi_enc: call cec_s_conn_info()

Set the connector info for the CEC adapter. This helps
userspace to associate the CEC device with the HDMI connector.

Tested on a Cubieboard.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Tested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190823112427.42394-3-hverkuil-cisco@xs4all.nl