sw64: kvm: add definitions for kvm

Sunway inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SPZD


CVE: NA

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Add KVM_SW64_VCPU_INIT definition for SW64 vcpu init. Introduce
KVM_SW64_GET_VCB and KVM_SW64_SET_VCB definitions to save and
restore vcpu's context for hot-snapshot.

Signed-off-by: Gu Zitao <guzitao@wxiat.com> #openEuler_contributor
Signed-off-by: Laibin Qiu <qiulaibin@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>