KVM: ARM: vgic: abstract EISR bitmap access

Move the GICH_EISR access to its own function.

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 38864f5e..ccb9b59 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -86,6 +86,7 @@
 	void	(*set_lr)(struct kvm_vcpu *, int, struct vgic_lr);
 	void	(*sync_lr_elrsr)(struct kvm_vcpu *, int, struct vgic_lr);
 	u64	(*get_elrsr)(const struct kvm_vcpu *vcpu);
+	u64	(*get_eisr)(const struct kvm_vcpu *vcpu);
 };
 
 struct vgic_dist {