EGLFS: It's impossible to switch language when you load other keymap (using QEglFSFunctions::loadKeymap(const QString&))

I need to change keymap under platforms eglfs and linuxfb (without wayland). I use the function QEglFSFunctions::loadKeymap(const QString&), but there's no way to switch between english and another language than to press AltGr as a modifier. But I need to change between languages from my program. I would like to add the function that allows to change the language. And also to add the ability to switch the keymap and layout for the platform linuxfb. These additions in the attached patch.