Input: synaptics - enable InterTouch for ThinkPad X1E 1st gen

Tested on my own laptop, touchpad feels slightly more responsive with
this on, though it might just be placebo.

Signed-off-by: Ilya Katsnelson <me@0upti.me>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20200703143457.132373-1-me@0upti.me
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>