wlan: Abort existing remain on channel.

Firmware can't handle WLAN_HAL_SET_PREF_NETWORK_REQ in between the
scan (WLAN_HAL_INIT_SCAN_REQ and FINISH_SCAN_REQ/RSP).
Hence abort existing remain on channel before enabling the sched/pno
scan.

Change-Id: I25abf7aa3a147a5abea6f7edcd42db8fdcfed7f1
CRs-Fixed: 744157
wlan: prefill the memory allocated in DMA region with 0s

Modify the API used to return memory in DMA region to
prefill the allocated memory with 0s, this has to be
done to prevent garbage values persisting in memory
which can affect the system performance if the memory
is used to program hardware descriptors.

Change-Id: I98873aa0117ece5530db332e0c148151e263a8ca
CRs-Fixed: 730682
Wlan: Correct VOWIFI feature flag in __schBeaconProcessForSession

In __schBeaconProcessForSession(), incorrect feature flag is used for
VOWIFI feature. Replacing the incorrect flag with WLAN_FEATURE_VOWIFI

Change-Id: I512cc28a2201cee4ee95b7669178ef0c2b6ac196
CRs-Fixed: 744363
Wlan: Release 3.2.3.439

Release 3.2.3.439

Change-Id: I8b26c792b7e617cb7bed4314e4b0b5817b5615f5
CRs-Fixed: 688141