x86: Add Hygon Dhyana support.

x86: Add Hygon Dhyana support.

This patch fix Hygon Dhyana processor CPU Vendor ID detection
problem in glibc sysdep module, current glibc codes doesn't
recognize Dhyana CPU Vendor ID("HygonGenuine") and set kind to
arch_kind_other, which result to incorrect zero value for
__cache_sysconf() syscall. As Hygon Dhyana share most
architecture feature as AMD Family 17h, this patch add Hygon CPU
Vendor ID check and setup kind to arch_kind_amd and reuse AMD
code path, which lead to correct return value in
__cache_sysconf() syscall. we run the glibc test suite for both
Hygon Dhyana and AMD EPYC and found no failure case.

Background:
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).

Related Hygon kernel patch can be found on
http://lkml.kernel.org/r/5ce86123a7b9dad925ac583d88d2f921040e859b.1538583282.git.puwen@hygon.cn

Signed-off-by: fanjinke <fanjinke@hygon.cn>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>