KVM: x86: add kvm_arch_vcpu_postcreate callback, move TSC initialization

TSC initialization will soon make use of online_vcpus.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index be3e7bb..e6cfd43 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1853,6 +1853,7 @@
 	atomic_inc(&kvm->online_vcpus);
 
 	mutex_unlock(&kvm->lock);
+	kvm_arch_vcpu_postcreate(vcpu);
 	return r;
 
 unlock_vcpu_destroy: