psci_cpu_on
err = psci_cpu_on(*reg, pmap_kextract((vm_offset_t)mpentry), id);
rv = psci_cpu_on(*reg, pmap_kextract((vm_offset_t)mpentry), id);
err = psci_cpu_on(target_cpu, entry, cpuid);
int psci_cpu_on(unsigned long, unsigned long, unsigned long);