SSL support is broken when cross compiling with linux host for windows target

If you try to build windows binaries by cross compiling on linux then the library name lookup for openssl fails.

For example, here is one work-around that has been used:
https://build.opensuse.org/package/view_file?file=qt-4.7.3-fix-loading-openssl.patch&package=mingw32-libqt4&project=windows%3Amingw%3Awin32&rev=f543b9c22f2d3cf1ac6f9d53b4203824

We really should solve this properly.