of: Add vendor prefix for Menlo Systems GmbH

Add vendor prefix for Menlo Systems GmbH, http://www.menlosystems.com/ .

Signed-off-by: Marek Vasut <[e-mail]>
Cc: Fabio Estevam <[e-mail]>
Cc: NXP Linux Team <[e-mail]>
Cc: Rob Herring <[e-mail]>
Cc: Shawn Guo <[e-mail]>
Cc: [e-mail]
Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

Documentation/devicetree/bindings/vendor-prefixes.txt

···
 melfas	MELFAS Inc.
 mellanox	Mellanox Technologies
 memsic	MEMSIC Inc.
+menlo	Menlo Systems GmbH
 merrii	Merrii Technology Co., Ltd.
 micrel	Micrel Inc.
 microchip	Microchip Technology Inc.