ARM: KVM: fix non-VGIC compilation

Add a stub for kvm_vgic_addr when compiling without
CONFIG_KVM_ARM_VGIC. The usefulness of this configurarion is extremely
doubtful, but let's fix it anyway (until we decide that we'll always
support a VGIC).
Reported-by: Michele Paolino <m.paolino@virtualopensystems.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

include/kvm/arm_vgic.h

@@ -171,6 +171,11 @@ static inline int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 add
 	return 0;
 }
 
+static inline int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write)
+{
+	return -ENXIO;
+}
+
 static inline int kvm_vgic_init(struct kvm *kvm)
 {
 	return 0;