[yocto] [meta-mingw] Patch needed to let linker find lto plugin

[winfried.dobbe at xmsnet.nl]

Recently the meta-mingw layer was updated to krogoth by Juro Bystricky. 
Thanks !
However when I build it as-is, the linker fails because it can't load 
the lto plugin.

After applying commit a06e473590207f72b11d273a09de2c8a889c381e from 
meta-mingw-contrib (by Mark Hatle), the error disappeared.

See: 
http://git.yoctoproject.org/cgit/cgit.cgi/meta-mingw-contrib/commit/?h=mgh/jetho/meta-mingw&id=a06e473590207f72b11d273a09de2c8a889c381e

I think this patch needs to be applied also to the meta-mingw main 
repository.

regards,
W. Dobbe