vmm: Add Hygon Dhyana support

[puwen_hygon.cn]

Summary

The Hygon Dhyana processor has the SVM feature as AMD family 17h does.
To create VMs successfully on Hygon platforms, add Hygon Dhyana support
to the vmm infrastructure by sharing the code path of AMD family 17h.

[grehan]

sys/amd64/vmm/vmm_util.h

38

I think you could create a new function, vmm_is_svm(), and roll the AMD and Hygon check into that. The is_amd/is_hygon routines could be removed.

[emaste]

I agree with @grehan, vmm_is_svm is preferable rather than changing all cases to vmm_is_amd || vmm_is_hygon

[puwen_hygon.cn]

In D23553#517246, @emaste wrote:

I agree with @grehan, vmm_is_svm is preferable rather than changing all cases to vmm_is_amd || vmm_is_hygon

OK, will use vmm_is_svm instead.

sys/amd64/vmm/vmm_util.h

38

OK, will add function vmm_is_svm().

[puwen_hygon.cn]

Create a new function vmm_is_svm(), and roll the AMD and Hygon check into that.