CVE-2025-38366 LoongArch: KVM: Check validity of "num_cpu" from user space

In the Linux kernel, the following vulnerability has been resolved: LoongArch: KVM: Check validity of "numcpu" from user space The maximum supported cpu number is EIOINTCROUTEMAXVCPUS about irqchip EIOINTC, here add validation about cpu number to avoid array pointer overflow...