Need a way to disable keyboard, mouse, and touch screen separately in an environment where libudev is not available

Customer wants a way to individually enable/disable the keyboard, mouse, and touch panel on a Linux system built with the -no-udev option. Even if those devices are connected when the Qt application starts, the Qt application should not accept those events.

Currently, for keyboard, mouse and touch panel, for QT_QPA_EVDEV_KEYBOARD_PARAMETER, QT_QPA_EVDEV_MOUSE_PARAMETER and QT_QPA_EVDEV_TOUCHSCREEN_PARAMETER, It could be disabled by specifying a non-existent device file name (e.g. /dev/foo).

In the early days of Qt5, if udev was disabled, these devices were disabled even if they were connected.