add support for the Hygon Dhyana architecture
Chengdu Haiguang IC Design Co., Ltd (Hygon) is a Joint Venture
between AMD and Haiguang Information Technology Co.,Ltd., aims
at providing high performance x86 processor for China server
market. Its first generation processor codename is Dhyana, which
originates from AMD technology and shares most of the architecture
with AMD's family 17h, but with different CPU Vendor ID ("HygonGenuine")
/Family series number (Family 18h).