Revert "Input: synaptics - enable RMI mode for X1 Extreme 2nd Generation"

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.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/mouse/synaptics.c

@@ -177,7 +177,6 @@ static const char * const smbus_pnp_ids[] = {
 	"LEN0096", /* X280 */
 	"LEN0097", /* X280 -> ALPS trackpoint */
 	"LEN009b", /* T580 */
-	"LEN0402", /* X1 Extreme 2nd Generation */
 	"LEN200f", /* T450s */
 	"LEN2054", /* E480 */
 	"LEN2055", /* E580 */