add deps on mkldnn for var_type_traits (#45629)

paddle/fluid/framework/CMakeLists.txt

@@ -188,6 +188,13 @@ cc_library(
 if(WITH_GPU)
   target_link_libraries(var_type_traits dynload_cuda)
 endif()
+
+# every source file that includes "dnnl.h" must depends on mkldnn
+# or, the first one should depends on mkldnn
+if(WITH_MKLDNN)
+  add_dependencies(var_type_traits mkldnn)
+endif()
+
 cc_test(
   var_type_traits_test
   SRCS var_type_traits_test.cc