ltr502als.c: Increase the sample integration circle of proximity sensor

ltr502als.c: Increase the sample integration circle of proximity sensor

BZ: 18196

During voice call display may go off by an accidental swipe. To avoid
that, we increase the sample intergration circle of proximity sensor.
After this change, it will take more time to trigger proximity interrupt
than before.

Change-Id: Id6fe644a9daf610de31398b2485914c43b7600d9
Signed-off-by: Leo Yan <leo.yan@intel.com>
Reviewed-on: http://android.intel.com:8080/29996
Reviewed-by: Liu, Hong <hong.liu@intel.com>
Reviewed-by: Du, Alek <alek.du@intel.com>
Tested-by: Wang, Zhifeng <zhifeng.wang@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>