Input: synaptics - adjust min/max on Thinkpad E540

The LEN2006 Synaptics touchpad (as found in Thinkpad E540) returns wrong
min max values.

touchpad-edge-detector output:
>  Touchpad SynPS/2 Synaptics TouchPad on /dev/input/event6
>  Move one finger around the touchpad to detect the actual edges
>  Kernel says:    x [1472..5674], y [1408..4684]
>  Touchpad sends: x [1264..5675], y [1171..4688]

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88211


Cc: stable@vger.kernel.org
Signed-off-by: Binyamin Sagal <bensagal@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>