Bluetooth: hci_sync: Enable advertising when LL privacy is enabled

This enables advertising when LL privacy is enabled and changes the
command sequence when resolving list is updated to also account for when
advertising is enabled using the following sequence:

If there are devices to scan:

Disable Scanning -> Update Accept List ->
use_ll_privacy((Disable Advertising) -> Disable Resolving List ->
Update Resolving List -> Enable Resolving List -> (Enable Advertising)) ->
Enable Scanning

Otherwise:

Disable Scanning

Errors during the Update Accept List stage are handled gracefully by
restoring any previous state (e.g. advertising) and disabling the use of
accept list as either accept list or resolving list could not be
updated.

Tested with:

mgmt-tester -s "LL Privacy"

Test Summary
------------
LL Privacy - Add Device 1 (Add to WL)                Passed
LL Privacy - Add Device 2 (Add to RL)                Passed
LL Privacy - Add Device 3 (Enable RL)                Passed
LL Privacy - Add Device 4 (2 Devices to WL)          Passed
LL Privacy - Add Device 5 (2 Devices to RL)          Passed
LL Privacy - Add Device 6 (RL is full)               Passed
LL Privacy - Add Device 7 (WL is full)               Passed
LL Privacy - Add Device 8 (Disable Adv)              Passed
LL Privacy - Add Device 9 (Multi Adv)                Passed
LL Privacy - Add Device 10 (Multi Dev and Multi Adv) Passed
LL Privacy - Remove Device 1 (Remove from WL)        Passed
LL Privacy - Remove Device 2 (Remove from RL)        Passed
LL Privacy - Remove Device 3 (Disable RL)            Passed
LL Privacy - Remove Device 4 (Disable Adv)           Passed
LL Privacy - Remove Device 5 (Multi Adv)             Passed
LL Privacy - Start Discovery 1 (Disable RL)          Passed
LL Privacy - Start Discovery 2 (Disable RL)          Passed
Total: 18, Passed: 18 (100.0%), Failed: 0, Not Run: 0

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>