dt-bindings: vendor-prefixes: Add Liontron name

Liontron is a company based in Shenzen, China, making industrial
development boards and embedded computers, mostly using Rockchip and
Allwinner SoCs.

Add their name to the list of vendors.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20250505164729.18175-2-andre.przywara@arm.com


Signed-off-by: Chen-Yu Tsai <wens@csie.org>