dt-bindings: add vendor prefix for bananapi

Add BIPAI KEJI LIMITED which is a company dedicating to design and
manufacture bananapi open hardware.

Website: http://www.banana-pi.org/

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -44,6 +44,7 @@ avia	avia semiconductor
 avic	Shanghai AVIC Optoelectronics Co., Ltd.
 axentia	Axentia Technologies AB
 axis	Axis Communications AB
+bananapi BIPAI KEJI LIMITED
 boe	BOE Technology Group Co., Ltd.
 bosch	Bosch Sensortec GmbH
 boundary	Boundary Devices Inc.