Input: synaptics - enable InterTouch for ThinkPad P1/X1E gen 2

With the new RMI4 F3A support, we're now able to enable full RMI4
support for this model. We also tidy up the comments a bit, as the X1E
is essentially the same computer as the P1.

Acked-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20200930225046.173190-3-Jason@zx2c4.com


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