wcnss: set property of wlan.driver.ath to 0

The ability to run shell scripts as a service is removed and thus
only essential functionality from the init.qcom.wifi.sh is set in
wcnss-service. The wlan.driver.ath property needs to be set for
LOWI module to work.

Change-Id: I6ccec41d1fd80fc0cefb7e6feb9528a7a702efbb
CRs-Fixed: 584329