cpu: Make kvm-stub.o available outside softmmu

It will provide stubs for *-user targets once softmmu-specific calls
are attempted from common CPU code.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/kvm-stub.c b/kvm-stub.c
index 5f52186..b228378 100644
--- a/kvm-stub.c
+++ b/kvm-stub.c
@@ -12,10 +12,13 @@
 
 #include "qemu-common.h"
 #include "hw/hw.h"
-#include "hw/pci/msi.h"
 #include "cpu.h"
 #include "sysemu/kvm.h"
 
+#ifndef CONFIG_USER_ONLY
+#include "hw/pci/msi.h"
+#endif
+
 KVMState *kvm_state;
 bool kvm_kernel_irqchip;
 bool kvm_async_interrupts_allowed;
@@ -111,6 +114,7 @@
     return 1;
 }
 
+#ifndef CONFIG_USER_ONLY
 int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
 {
     return -ENOSYS;
@@ -134,3 +138,4 @@
 {
     return -ENOSYS;
 }
+#endif