KVM: ARM: vgic: move underflow handling to vgic_ops

Move the code dealing with LR underflow handling to its own functions,
and make them accessible through vgic_ops.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 4857508..cdfa5d9 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -88,6 +88,8 @@
 	u64	(*get_elrsr)(const struct kvm_vcpu *vcpu);
 	u64	(*get_eisr)(const struct kvm_vcpu *vcpu);
 	u32	(*get_interrupt_status)(const struct kvm_vcpu *vcpu);
+	void	(*enable_underflow)(struct kvm_vcpu *vcpu);
+	void	(*disable_underflow)(struct kvm_vcpu *vcpu);
 };
 
 struct vgic_dist {