KVM: Move cpuid code to new file

The cpuid code has grown; put it into a separate file.

Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8f19d91..4ceced2 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -18,6 +18,7 @@
 
 #include "irq.h"
 #include "mmu.h"
+#include "cpuid.h"
 
 #include <linux/kvm_host.h>
 #include <linux/module.h>