Fixed license for all basic types

Just a simple fix and nobody will bother to do it next time.
> The files that had MIT license header should retain the license name and refer to LICENSE.txt for the full license.

Its not a good idea - because MonoGame already contains files with removed MIT license
for example -
https://github.com/mono/MonoGame/commit/7fe7b4bbcaa8d876ee00c4809fbb2f89da7cd8b4