Log Message:
security/libfido2: Mark BROKEN_EXCEPT_ON_PLATFORM

Upstream has (ignoring Windows) explicit code for 6 platforms,
covering most pkgsrc usage except SunOS.  Because it ought to build on
systems that can support usbhid (and upstream even has an option to
disable usbhid), not building is BROKEN rather than ONLY_FOR.

Tested to build and pass tests on NetBSD 10 amd64.