input: touchscreen: st: add state machine for TUI error handling

Introduce state machine for various checkpoints in trusted touch usecase.
In error scenarios, this state machine helps driver to rollback to
previous state.

Change-Id: I8c8a0d23c0c44ed5e4be5e623680a250636b78f4
Signed-off-by: Shashank Babu Chinta Venkata <sbchin@codeaurora.org>