dt-bindings: vendor-prefix: add Shenzhen Feixin Photoelectics Co., Ltd

Shenzhen Feixin Photoelectics Co., Ltd is a company to provide LCD
modules.

Add its vendor prefix.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200116033636.512461-2-icenowy@aosc.io