kvm: Enable use of kvm_irqchip_in_kernel in hwlib code

Provide a dummy kvm_kernel_irqchip so that kvm_irqchip_in_kernel can be
used by code that is not under CONFIG_KVM protection.

Signed-off-by: Jan Kiszka <[email protected]>
Signed-off-by: Avi Kivity <[email protected]>
diff --git a/kvm-stub.c b/kvm-stub.c
index b4cf03f..ec9a364 100644
--- a/kvm-stub.c
+++ b/kvm-stub.c
@@ -18,6 +18,7 @@
 #include "kvm.h"
 
 KVMState *kvm_state;
+bool kvm_kernel_irqchip;
 
 int kvm_init_vcpu(CPUArchState *env)
 {