modules/input: Only build quartz module if we're targeting quartz
modules/input: Only build quartz module if we're targeting quartz

Otherwise the build is broken on GNU/Linux and Win32.

johne53/MB3Gtk-2,Distrotech/gtk,johne53/MB3Gtk-2,johne53/MB3Gtk-2,Distrotech/gtk,johne53/MB3Gtk-2,johne53/MB3Gtk-2,Distrotech/gtk,Distrotech/gtk,Distrotech/gtk