Input: trackpoint - force 3 buttons if 0 button is reported
Lenovo introduced trackpoint compatible sticks with minimum PS/2 commands.
They supposed to reply with 0x02, 0x03, or 0x04 in response to the
"Read Extended ID" command, so we would know not to try certain extended
commands. Unfortunately even some trackpoints reporting the original IBM
version (0x01 firmware 0x0e) now respond with incorrect data to the "Get
Extended Buttons" command: