arch: loongarch: enable KVM in deepin_loongarch_desktop_defconfig

[MingcongBai]

Enable KVM support for our desktop defconfig.

[deepin-ci-robot]

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[deepin-ci-robot]

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关键摘要:

• 在CONFIG_VIRTUALIZATION和CONFIG_KVM配置中使用了m选项，这可能意味着系统将支持虚拟化。需要确认这是否符合项目需求和安全性标准。
• 新增的CONFIG_VIRTUALIZATION和CONFIG_KVM配置是否已经通过了所有相关的单元测试和集成测试。
• 检查是否有必要在deepin_loongarch_desktop_defconfig中启用虚拟化和KVM支持，因为这可能会影响系统的性能和稳定性。

是否建议立即修改:

• 是，需要确保新增的配置是经过充分测试的，并且与项目的整体策略相符合。同时，应该评估启用虚拟化和KVM支持对系统性能和稳定性可能的影响。