KVM: PPC: Fix compile warning

KVM compilation fails with the following warning:

include/linux/kvm_host.h: In function 'kvm_irq_routing_update':
include/linux/kvm_host.h:679:2: error: 'struct kvm' has no member named 'irq_routing'

That function is only used and reasonable to have on systems that implement
an in-kernel interrupt chip. PPC doesn't.

Fix by #ifdef'ing it out when no irqchip is available.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

include/linux/kvm_host.h

@@ -673,11 +673,13 @@ static inline int kvm_irqfd(struct kvm *kvm, int fd, int gsi, int flags)
 
 static inline void kvm_irqfd_release(struct kvm *kvm) {}
 
+#ifdef CONFIG_HAVE_KVM_IRQCHIP
 static inline void kvm_irq_routing_update(struct kvm *kvm,
 					  struct kvm_irq_routing_table *irq_rt)
 {
 	rcu_assign_pointer(kvm->irq_routing, irq_rt);
 }
+#endif
 
 static inline int kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
 {