Bluetooth: Add tracking of advertising address type

To know the real source address for incoming connections (needed e.g.
for SMP) we should store the own_address_type parameter that was used
for the last HCI_LE_Write_Advertising_Parameters command. This patch
adds a proper command complete handler for the command and stores the
address type in a new adv_addr_type variable in the hci_dev struct.

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