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/python/led.py

@@ -3,24 +3,7 @@
 # Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
 # Copyright (c) 2018 Linaro Ltd.
 #
-# Permission is hereby granted, free of charge, to any person obtaining
-# a copy of this software and associated documentation files (the
-# "Software"), to deal in the Software without restriction, including
-# without limitation the rights to use, copy, modify, merge, publish,
-# distribute, sublicense, and/or sell copies of the Software, and to
-# permit persons to whom the Software is furnished to do so, subject to
-# the following conditions:
-#
-# The above copyright notice and this permission notice shall be
-# included in all copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
-# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
-# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
-# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
-# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+# SPDX-License-Identifier: MIT
 #
 # Example Usage: Reads maximum brightness value for user1 led and turns it
 #                on/off depending on current state. Then sets led trigger