touchscreen: synaptics_dsx: set absolute axes for touchscreen

Android considers that minimum and maximum values of the
ABS_MT_POSITION_X and ABS_MT_POSITION_Y axes define the bounds
of the active area of the device in device-specific surface
units. These axes are stored inside the input_absinfo array of
the registered input devices. For touchscreen devices, these
axes are normally configured during driver's probe time.
However, some usecases would want to shrink or expand this
active area of the touch device on runtime. This patch adds
flexibility to configure these axes for touch screen's
corresponding input device.

Change-Id: I45e02bb93f02365ae44cffb04e8674244e4e372b
Signed-off-by: Shantanu Jain <shjain@codeaurora.org>