input: synaptic_dsx: configure touch panel boundary coordinates

For some touch controller nodes, there is no explicit device tree
property specifying the touch coordinates range. In this case,
touch coordinates range is read explicitly from the sensor.
Add support for configuring the maximum X and Y coordinates of
touch driver's input device based for such cases.

Change-Id: Ic86aa90598aa1a7935f2562753ccf863edba1c9f
Signed-off-by: Sarada Prasanna Garnayak <c_sgarna@codeaurora.org>