input: touchscreen: add touch to wake feature in ITEtech driver

Add touch to wake feature in ITE tech touchscreen driver.
The touchscreen interrupt is configured as wakeable interrupt,
so TS can be used to wake the device from suspend state.

Change-Id: I8da53ab4f03237b8652cd5891eadbffa752d72d3
Signed-off-by: Shantanu Jain <shjain@codeaurora.org>