drm/omap: display: Add displays in sorted order to the panel_list

Keep the panel_list ordered according to aliases. The DRM connectors will
be created following the panel_list. By keeping the list ordered the DRM
connectors will be created in the same order regardless of the driver
probe order.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>