drm/panel: Add support for Chunghwa CLAA070WP03XG panel

The Chunghwa CLAA070WP03XG is a 7" 1280x800 panel, which can be
supported by the simple panel driver.

Signed-off-by: Randy Li <ayaka@soulik.info>
Signed-off-by: Thierry Reding <treding@nvidia.com>