Bluetooth : HAL change for wake state change callback

This change includes function declaration for the wake state
change callback. This is to implement wake lock acquire/release
machanism to ensure the power saving when the ACL is not active.

Change-Id: I3205458e29521efd0d01a66a314fad499763cb87
CRs-fixed: 576239
Bluetooth: Stack certification.

Stack certification changes for L2CAP, SDP and RFCOMM

Change-Id: If322fff2c5dcf915333574aaae0394f130498305
BT: Added new file bt_multi_hf.h

The new file contents are copied from initial
Bluetooth open source release of file "bt_hf.h"
revision 05f49546. This file will be used for
code modifications for Multi HF implementation.

Change-Id: I6da6d805bdfe3d44b6ec37302a7318cd10f3420c