kvm: add stub for update msi route

Will be used by virtio-pci.

Signed-off-by: Michael S. Tsirkin <[email protected]>
diff --git a/kvm-stub.c b/kvm-stub.c
index 5b97152..81f8967 100644
--- a/kvm-stub.c
+++ b/kvm-stub.c
@@ -131,6 +131,11 @@
 {
 }
 
+int kvm_irqchip_update_msi_route(KVMState *s, int virq, MSIMessage msg)
+{
+    return -ENOSYS;
+}
+
 int kvm_irqchip_add_irqfd_notifier(KVMState *s, EventNotifier *n, int virq)
 {
     return -ENOSYS;