BTSTACK release-v3.8.0

BTSTACK3.8 is BT5.4 certified. QDID: 219623.
This release contains bug fixes and and an enhancement listed below.

• Support for PAwR added, refer to wiced_bt_ble.h for details of interfaces
• Added utility functions for Advertisement encryption and decryption, see wiced_bt_ble_encrypt_adv_packet and wiced_bt_ble_decrypt_adv_packet
• Implementation of BT Core spec erratum 22240
• Added API wiced_bt_app_serialize_function that can be called by applications to serialize the execution of an application function in the BT stack context
• Updates to optimize the code size for Dual-mode stack
• Support for connection subrate request procedure, added the API wiced_bt_l2cap_subrate_request and related events
• Added API wiced_bt_ble_notify_on_device_address_change to notify the application on device address change via BTM_BLE_DEVICE_ADDRESS_UPDATE_EVENT event.
• Other bug fixes and documentation enhancements.