msm: input: touchscreen: fix i2c error when suspend

When device suspend, disable the gpio irq to avoid i2c read errors.
For irq efficiency, change the "request_irq" to be "request_threaded_irq".

Change-Id: I46c403e962a2dbcec967707c444a14368a16a4f8
Signed-off-by: Fei Mao <feim1@codeaurora.org>