TSLib: Changes made for using TSLib

These changes are made to make use of TSLib to calibrate events
generated from touch screen.

ts_read in tslib reads raw events written by touchscreen driver in
/dev/input/event0. ts_read then packages all the events between each
EV_SYN and sends the final calibrated values to EventHub.cpp along with
the list of events raw read. We then send each event seperately in this
list to the upper layer.

Change-Id: If529e5687620df50cf725edbaa321953df50c0a5