This reverts commit 68b9c5066e39af41d3448abfc887c77ce22dd64d.

Ugh, I really dropped the ball on this one :\. So as it turns out RMI4
works perfectly fine on the X1 Extreme Gen 2 except for one thing I
didn't notice because I usually use the trackpoint: clicking with the
touchpad. Somehow this is broken, in fact we don't even seem to indicate
BTN_LEFT as a valid event type for the RMI4 touchpad. And, I don't even
see any RMI4 events coming from the touchpad when I press down on it.
This only seems to work for PS/2 mode.

Since that means we have a regression, and PS/2 mode seems to work fine
for the time being - revert this for now. We'll have to do a more
thorough investigation on this.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20191119234534.10725-1-lyude@redhat.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>