input: atmel_mxt_ts: Disabling secure touch for power events.

Any power event in the driver happening while secure touch is
active will cause it to close.
Additional fix to make sure secure touch events are forwarded
only if all previous events have already been processed.

Change-Id: I57f7cb45e2e53a923b9ab3b7c9baa34f1d3f9b5f
Acked-by: Christian Bolis <cbolis@qti.qualcomm.com>
Signed-off-by: Amy Maloche <amaloche@codeaurora.org>