devicetree: add vendor prefix for Vivante Corporation

Trivial patch to add Vivante Corporation to the list of
devicetree vendor prefixes.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -238,6 +238,7 @@ v3	V3 Semiconductor
 variscite	Variscite Ltd.
 via	VIA Technologies, Inc.
 virtio	Virtual I/O Device Specification, developed by the OASIS consortium
+vivante	Vivante Corporation
 voipac	Voipac Technologies s.r.o.
 wexler	Wexler
 winbond Winbond Electronics corp.