of: Add vendor prefix for BOE Technology Group

BOE Technology Group Co., Ltd. is a supplier of semiconductor display
technologies, products and services.

Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
[treding@nvidia.com: add commit message, fixup subject]
Signed-off-by: Thierry Reding <treding@nvidia.com>

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -33,6 +33,7 @@ auo	AU Optronics Corporation
 avago	Avago Technologies
 avic	Shanghai AVIC Optoelectronics Co., Ltd.
 axis	Axis Communications AB
+boe	BOE Technology Group Co., Ltd.
 bosch	Bosch Sensortec GmbH
 boundary	Boundary Devices Inc.
 brcm	Broadcom Corporation