dt-bindings: documenting compatible string vendor "visionox"

Documenting compatible string vendor "visionox" in vendor-prefix yaml file.
Signed-off-by: Harigovindan P <harigovi@codeaurora.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200429054515.4976-2-harigovi@codeaurora.org

Documentation/devicetree/bindings/vendor-prefixes.yaml

@@ -1043,6 +1043,8 @@ patternProperties:
     description: Tronsmart
   "^truly,.*":
     description: Truly Semiconductors Limited
+  "^visionox,.*":
+    description: Visionox
   "^tsd,.*":
     description: Theobroma Systems Design und Consulting GmbH
   "^tyan,.*":