Fix breaksage due to IREE ukernel API change

Change-Id: I9a2b2ba4379573ee906945d314244facc81a812f

vmvx_ukernel/CMakeLists.txt

diff --git a/vmvx_ukernel/CMakeLists.txt b/vmvx_ukernel/CMakeLists.txt
index cf4edb3..ecc70bc 100644
--- a/vmvx_ukernel/CMakeLists.txt
+++ b/vmvx_ukernel/CMakeLists.txt
@@ -14,6 +14,7 @@
     "${IREE_RUNTIME_SOURCE_DIR}/builtins/ukernel/pack_tile.c"
     "${IREE_RUNTIME_SOURCE_DIR}/builtins/ukernel/unpack.c"
     "${IREE_RUNTIME_SOURCE_DIR}/builtins/ukernel/unpack_tile.c"
+    "${IREE_RUNTIME_SOURCE_DIR}/builtins/ukernel/weak.c"
   DEPS
     iree::builtins::ukernel::internal_headers
   PUBLIC