[PORT FROM R2] atomisp: mt9e013: add lock protection to sensor's ioctl

[PORT FROM R2] atomisp: mt9e013: add lock protection to sensor's ioctl

BZ: 17272

Currently mt9e013 sensor lacks lock protection for concurrent ioctl
calls which may lead to racing condition.
This patch adds missing locks.

Change-Id: Ia0d3ca5156491a0cda169bedc7fe8731fffda5cc
Orig-Change-Id: I90f3cdca7c5b0cb7cf524244e8a4bf806d187223
Signed-off-by: David Cohen <david.a.cohen@intel.com>
Reviewed-on: http://android.intel.com:8080/24937
Reviewed-by: Koskinen, Ilkka <ilkka.koskinen@intel.com>
Reviewed-by: Wang, Wen W <wen.w.wang@intel.com>
Tested-by: Koski, Anttu <anttu.koski@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>
Reviewed-on: http://android.intel.com:8080/28021
Reviewed-by: Tuominen, TeemuX <teemux.tuominen@intel.com>
Reviewed-by: Koski, Anttu <anttu.koski@intel.com>