input: touchscreen: synaptics_dsx: Add secure touch support

Add secure touch support to the synaptics_dsx driver.
Expose the new interface through sysfs, to enable/disable
secure touch, and to wait for touch events. Also add
support for QUP ownership transfer to other subsystems to
support the secure touch usecase.

Change-Id: I9ff28dc193ab3c1eb7b425961ebc10a9cf75b8be
Signed-off-by: Ritesh Kumar <riteshk@codeaurora.org>