Use LF eol-style svn property for all Unix-only files.

At least with some of them (e.g. tiffconf.h) using native EOLs under Windows
confuses MinGW/MSYS and results in build failures. As all these files are only
used under Unix or in Unix-like environments, use Unix EOLs for them
everywhere.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73788 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775