input: touchscreen: st: cancel pending resume work

Before initiating trusted touch, cancel any pending
suspend or resume work and wait for already scheduled worker
to finish.

Change-Id: I9eb89a76e7238bf2ce18d319b9c50f2da784c703
Signed-off-by: Shashank Babu Chinta Venkata <sbchin@codeaurora.org>