drm/panel: panel-simple: Add connector_type for EDT ETM0700G0DH6 panel

Fix the warning message "missing connector type" by adding connector_type
for EDT ETM0700G0DH6 panel.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201020094910.4756-1-biju.das.jz@bp.renesas.com