drm/panel: panel-simple: Set OSD070T1718 panel type

The OSD070T1718 is a DPI panel, set its type accordingly.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190904133723.30418-1-laurent.pinchart@ideasonboard.com