Fix a breakage due to IREE upstream renaming

Change-Id: Ifc850bbc01893e651b8c8ad469d73cc20db1c3b6

ukernel/CMakeLists.txt

diff --git a/ukernel/CMakeLists.txt b/ukernel/CMakeLists.txt
index f69f8eb..43240e1 100644
--- a/ukernel/CMakeLists.txt
+++ b/ukernel/CMakeLists.txt
@@ -30,13 +30,13 @@
   HDRS
     "${IREE_RUNTIME_SOURCE_DIR}/builtins/ukernel/api.h"
   SRCS
+    "${IREE_RUNTIME_SOURCE_DIR}/builtins/ukernel/fallback.c"
     "${IREE_RUNTIME_SOURCE_DIR}/builtins/ukernel/mmt4d.c"
     "${IREE_RUNTIME_SOURCE_DIR}/builtins/ukernel/pack.c"
     "${IREE_RUNTIME_SOURCE_DIR}/builtins/ukernel/pack_tile.c"
     "${IREE_RUNTIME_SOURCE_DIR}/builtins/ukernel/query_tile_sizes.c"
     "${IREE_RUNTIME_SOURCE_DIR}/builtins/ukernel/unpack.c"
     "${IREE_RUNTIME_SOURCE_DIR}/builtins/ukernel/unpack_tile.c"
-    "${IREE_RUNTIME_SOURCE_DIR}/builtins/ukernel/weak.c"
     "${PREFIX_UKERNEL}/mmt4d_tile.c"
   DEPS
     iree::builtins::ukernel::internal_headers