Input: tsc40 - remove wrong announcement of pressure support

The tsc40 driver announces it supports the pressure event, but will never
send one. The announcement will cause tslib to wait for such events and
sending all touch events with a pressure of 0. Removing the announcement
will make tslib fall back to emulating the pressure on touch events so
everything works as expected.

Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>