drm: panels: Add MAINTAINERS entry for LVDS panel driver

As the DRM LVDS panel driver uses a different approach to DT bindings
compared to what Thierry Reding advocates, add a specific MAINTAINERS
entry to avoid bothering Thierry with requests related to that driver.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>