cherry-pick request into stable for: HID: lenovo: Add middleclick_workaround sysfs knob for cptkbd

Hello, Please, add the following commit: 2814646f76f8518326964f12ff20aaee70ba154d HID: lenovo: Add middleclick_workaround sysfs knob for cptkbd Into stable versions: 5.10, 5.15, 6.1, 6.6, 6.7, 6.8 This versions received automatic backport of my previous attempts to detect properly-behaving patched firmware which suffer from false-positives causing regression for users of factory lenovo firmware. The commit adds an explicit sysfs control hence avoids any room for false positives and fixes the regression. Thanks.