dt-bindings: display: Add King Display KD035G6-54NT panel documentation

The KD035G6-54NT is a 3.5" 320x240 24-bit TFT LCD panel.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190603152555.23527-1-paul@crapouillou.net