FreeBSD evdev uses private headers

In https://github.com/qt/qtbase/commit/e6d0d202f3c3f296b6865a63d87a7c9182b63ae2 lagocs (reviewer) added #include of platform-specific includes for FreeBSD ( <dev/evdev/input.h> ). These headers are not intended for public consumption (says the maintainer of those platform-specific headers on FreeBSD). Please revert that change.

There is a downstream (FreeBSD) bug discussing this, https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=240964

There is a similar (revert) change in wlroots, also mentioned in that downstream bug, https://git.sr.ht/~sircmpwn/wlroots/commit/f80d174e8b179f3af80f7990529c3b0440846dca

Ironically this means that when packaging Qt on FreeBSD for the official ports tree, we'll be patching out that specific change for 5.13.0 and 5.13.1