qcacld-3.0: Clean up the wlan_hdd_power API

Clean up issues identified in wlan_hdd_power.h:
- Make sure all APIs have documentation
- Make sure all APIs adhere to the coding standard

Change-Id: I955b2eaec5f583d8d558df1dac7708b7b455e089
CRs-Fixed: 2275266
4 files changed