arch/tile: properly export __mb_incoherent for modules

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
diff --git a/arch/tile/lib/exports.c b/arch/tile/lib/exports.c
index ce5dbf5..1509c55 100644
--- a/arch/tile/lib/exports.c
+++ b/arch/tile/lib/exports.c
@@ -45,6 +45,9 @@
 EXPORT_SYMBOL(__copy_in_user_inatomic);
 #endif
 
+/* arch/tile/lib/mb_incoherent.S */
+EXPORT_SYMBOL(__mb_incoherent);
+
 /* hypervisor glue */
 #include <hv/hypervisor.h>
 EXPORT_SYMBOL(hv_dev_open);