dt-bindings: Add vendor prefix for Hirschmann

Hirschmann is building devices for automation and networking. Add them to the
vendor prefixes.
Signed-off-by: NKurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Documentation/devicetree/bindings/vendor-prefixes.yaml

@@ -441,6 +441,8 @@ patternProperties:
     description: HiDeep Inc.
   "^himax,.*":
     description: Himax Technologies, Inc.
+  "^hirschmann,.*":
+    description: Hirschmann Automation and Control GmbH
   "^hisilicon,.*":
     description: Hisilicon Limited.
   "^hit,.*":