spdx: add spdx tags to most files

Large change that removes the duplicated MIT notice withe a spdx tag

Signed-off-by: Thomas Ingleby <thomas.ingleby@intel.com>

examples/javascript/isr.js

@@ -1,4 +1,9 @@
 #!/usr/bin/env node
+/*
+ * Copyright (c) 2015 Intel Corporation.
+ *
+ * SPDX-License-Identifier: MIT
+ */
 
 "use strict";