Bluetooth: Add initial code for distributing local IRK

This code adds a HCI_PRIVACY flag to track whether Privacy support is
enabled (meaning we have a local IRK) and makes sure the IRK is
distributed during SMP key distribution in case this flag is set.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --cc include/net/bluetooth/hci.h
Simple merge

diff --cc include/net/bluetooth/hci_core.h
Simple merge

diff --cc net/bluetooth/smp.c
Simple merge