dt-bindings: Add vendor prefix for Leadtek Technology

Shenzhen Leadtek Technology Co., Ltd. produces for example display
and touch panels.

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191224112641.30647-1-heiko@sntech.de

Documentation/devicetree/bindings/vendor-prefixes.yaml

@@ -511,6 +511,8 @@ patternProperties:
     description: Lantiq Semiconductor
   "^lattice,.*":
     description: Lattice Semiconductor
+  "^leadtek,.*":
+    description: Shenzhen Leadtek Technology Co., Ltd.
   "^leez,.*":
     description: Leez
   "^lego,.*":