Try to fix build of qt5-gui in the presence of evdev-proto
In Qt 5.13, a "helpful" upstream added #includes of the interal
FreeBSD event headers; these conflict with evdev-proto headers.
Back out that helpful fix, and rely on evdev-proto everywhere
(in particular, for dependent ports that use evdev-proto themselves).
PR: 240965
Reported by: Walter Schwarzenfeld