[PORT FROM R2] atmel_mxt224: manually check calibration stop condition

[PORT FROM R2] atmel_mxt224: manually check calibration stop condition

BZ: 19465

If auto-calibration is stopped immaturely with wrong condition, certain
area of touchscreen is not working after calibrated with finger touching
on it.

Manually check the calibration stop condition to avoid auto-calibration
being stopped immaturely.

Change-Id: Ic6baa38c54d703862e4d57aa84ea5c8de7aaf8c8
Orig-Change-Id: I6280fb6a2171f5e5bf5f5ec0318fccaa9db0a5cb
Signed-off-by: Hong Liu <hong.liu@intel.com>
Reviewed-on: http://android.intel.com:8080/34007
Reviewed-by: Cai, Stanley W <stanley.w.cai@intel.com>
Tested-by: Wang, Zhifeng <zhifeng.wang@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>