drm/panel: Add Innolux EJ030NA 3.0" 320x480 panel

Add support for the Innolux/Chimei EJ030NA 3.0"
320x480 TFT panel.

This panel can be found in the LDKs, RS97 V2.1 and RG300 (non IPS)
handheld gaming consoles.

While being 320x480, it is actually a horizontal 4:3
panel with non-square pixels in delta arrangement.

Signed-off-by: Christophe Branchereau <cbranchereau@gmail.com>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210625121045.81711-2-paul@crapouillou.net