of: Add vendor prefix for Digi International Inc.

Using "digi" for Digi International Inc.
Additionally, this patch keep "dlink" entry sorted alphabetically.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Rob Herring <robh@kernel.org>
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 36b8530..fad44ca 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -35,6 +35,7 @@
 dallas	Maxim Integrated Products (formerly Dallas Semiconductor)
 davicom	DAVICOM Semiconductor, Inc.
 denx	Denx Software Engineering
+digi	Digi International Inc.
 dlink	D-Link Corporation
 dmo	Data Modul AG
 edt	Emerging Display Technologies