drm: bridge: thc63: Report input bus mode through bridge timings

Set a drm_bridge_timings in the drm_bridge, and use it to report the
input bus mode (single-link or dual-link). The other fields of the
timings structure are kept to 0 as they do not apply to LVDS buses.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>