atmel_mxt_ts: Change the touch calibration condition

atmel_mxt_ts: Change the touch calibration condition

BZ: 29396

When the screen is resumed, we won't do calibration if there is a
finger on the touch panel since that will cause the finger pressed
area has wrong calibration and couldn't detect the touch later.

Change-Id: I8c54f2629592e14bc30b3bea1e4f35bd0520a4cf
Signed-off-by: Leo Yan <leo.yan@intel.com>
Reviewed-on: http://android.intel.com:8080/49296
Reviewed-by: Liu, Hong <hong.liu@intel.com>
Reviewed-by: Du, Alek <alek.du@intel.com>
Tested-by: Tang, HaifengX <haifengx.tang@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>