input: atmel_mxt_ts: Fix screen unlock issue after resume

Fix screen unlock issue after resume by releasing all touches in
mxt_suspend and reseting the controller in mxt_resume.

CRs-Fixed: 484797

Change-Id: I3c076680357df9ca98f45e998af9b489907dbba5
Signed-off-by: Shantanu Jain <shjain@codeaurora.org>