Enable hotkey button again.

If there is no hotkey button there is a problem with joystick autoconfig files. The joystick hotkey button will not be recognized if there is no keyboard hotkey button. Most joystick autoconfig files use start + select to exit retroarch. Without a keyboard hotkey button retroarch will exit if start is pressed.

Old solution:  Escape is hotkey and exit button. Problem --> We cannot open RGUI with F1.
New solution: Remove exit button. Open RGUI if escape is pressed. We can quit retroarch from RGUI.