devicetree: add vendor prefix for Winstar Display Corp.

Winstar Display Corp. is specialized in LCD displays for embedded
products.
cf: http://www.winstar.com.tw

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -335,6 +335,7 @@ wd	Western Digital Corp.
 wetek	WeTek Electronics, limited.
 wexler	Wexler
 winbond Winbond Electronics corp.
+winstar	Winstar Display Corp.
 wlf	Wolfson Microelectronics
 wm	Wondermedia Technologies, Inc.
 x-powers	X-Powers