wlan: Improve W-Fi data transmission stablity

Update gDataInactivityTimeout parameters from 20 to 200ms to improve
wifi throughput when DUT connect to Broadcom solution Mobile Hotspot.

All credits go to XDA-member kalo86
http://forum.xda-developers.com/nexus-4/development/wifi-fix-updated-nexus-4-wireless-t2300873

Change-Id: I6541b439d6aebad5ff8e9b461ceaad7cbd338da7