wayland: Use dev/evdev/input.h on FreeBSD (GTK3)
The header linux/input.h used by GDK is specific to Linux. It is possible to get a few Linux headers on FreeBSD by installing v4l_compat, but it is usually better to use the one shipped with FreeBSD.
We prefer dev/evdev/input.h to linux/input.h here, so it will always use dev/evdev/input.h on FreeBSD regardless of v4l_compat.
Edited by Ting-Wei Lan