KVM: ia64: define kvm_lapic_enabled() to fix a compile error

The following patch

  commit 57ce1659316f4ca298919649f9b1b55862ac3826
  KVM: x86: In DM_LOWEST, only deliver interrupts to vcpus with enabled LAPIC's

ignored the fact that kvm_irq_delivery_to_apic() was also used by ia64.

We define kvm_lapic_enabled() to fix a compile error caused by this.
This will have the same effect as reverting the problematic patch for ia64.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/ia64/kvm/lapic.h

@@ -25,5 +25,6 @@ int kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,
 int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2);
 int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq);
 #define kvm_apic_present(x) (true)
+#define kvm_lapic_enabled(x) (true)
 
 #endif