xen/arm: implement HYPERVISOR_vcpu_op

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 99ce189..82d5e63 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -259,4 +259,5 @@
 EXPORT_SYMBOL_GPL(HYPERVISOR_hvm_op);
 EXPORT_SYMBOL_GPL(HYPERVISOR_memory_op);
 EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op);
+EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op);
 EXPORT_SYMBOL_GPL(privcmd_call);