Bluetooth: Update bt_conn_cb to pass bt_conn instead of bt_addr_le_t

Now that we have a publicly exposed connection object it makes sense
to pass that to the connection callbacks rather than an address.

Change-Id: I8e9b17733d1789539a83c3dbc7a778336d2b71ff
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
3 files changed