of: add aspeed to vendor-prefixes

ASPPED Technology Inc is a fabless IC-design company.  Their web site
is http://www.aspeedtech.com/.

Signed-off-by: Milton Miller <miltonm@us.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>

Author: mdmillerii

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -28,6 +28,7 @@ arm	ARM Ltd.
 armadeus	ARMadeus Systems SARL
 artesyn	Artesyn Embedded Technologies Inc.
 asahi-kasei	Asahi Kasei Corp.
+aspeed	ASPEED TECHNOLOGY Inc.
 atmel	Atmel Corporation
 auo	AU Optronics Corporation
 avago	Avago Technologies