ltr301als: Change the adc-lux conversion method

ltr301als: Change the adc-lux conversion method

BZ: 39399 41574

The adc-lux conversion is not accurate on the DV20, change the
algorithm and coefficent according to the vendor's advice.

Change-Id: I5a6e11c86c8553cd40732c9cf300421a69ac440b
Signed-off-by: Leo Yan <leo.yan@intel.com>
Reviewed-on: http://android.intel.com:8080/52892
Reviewed-by: Liu, Hong <hong.liu@intel.com>
Reviewed-by: Chen, Jie D <jie.d.chen@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>