dt-bindings: define vendor prefix for whwave, Inc.

Introduce vendor prefix for whwave, Inc.
for SD3078 rtc device.
Signed-off-by: Dianlong Li <long17.cool@163.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -430,6 +430,7 @@ vot	Vision Optical Technology Co., Ltd.
 wd	Western Digital Corp.
 wetek	WeTek Electronics, limited.
 wexler	Wexler
+whwave  Shenzhen whwave Electronics, Inc.
 wi2wi	Wi2Wi, Inc.
 winbond Winbond Electronics corp.
 winstar	Winstar Display Corp.