include: Add handsfree card driver registration
handsfree-audio: Add card driver registration
include: Add get/set data handsfree audio card
handsfree-audio: Implement get/set data
include: Refactor ofono_handsfree_card_create
handsfree-audio: Match new card API
hfp_hf_bluez5: Update to the new API
hfp_hf_bluez5: Set remote and local information
core: Add bt_str2ba() to bluetooth.h

This patch adds a utility Bluetooth function to convert Bluetooth
address from string to bdaddr_t.
handsfree_audio: Call driver remove() on removal