drm/panel: Add ABT Y030XX067A 3.0" 320x480 panel

Add support for the ShenZhen Asia Better Technology Ltd. Y030XX067A 3.0"
320x480 IPS panel.

This panel can be found in the YLM RG-280M, RG-300 and RG-99 handheld
gaming consoles. While being 320x480, it is actually a horizontal 4:3
panel with non-square pixels.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Christophe Branchereau <cbranchereau@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201101093150.8071-5-paul@crapouillou.net