Input: joydev - don't classify the vmmouse as a joystick

Joydev is currently thinking some absolute mice are joystick, and that
messes up games in VMware guests, as the cursor typically gets stuck in
the top left corner.

Try to detect the event signature of a VMmouse input device and back off
for such devices. We're still incorrectly detecting, for example, the
VMware absolute USB mouse as a joystick, but adding an event signature
matching also that device would be considerably more risky, so defer that
to a later merge window.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>