hammerhead: Add power HAL
hammerhead: Add power HAL

Change-Id: I3cc9978c81321cf4268b414254a360bd880bf41a

maruos/android_device_lge_hammerhead,maruos/android_device_lge_hammerhead,maruos/android_device_lge_hammerhead,maruos/android_device_lge_hammerhead