ARM: dts: renesas: Switch to panel-lvds bindings for Mitsubishi panels

The aa104xd12 and aa121td01 panels are LVDS panels, not DPI panels.
Use the correct DT bindings.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>