[nrf fromtree] Bluetooth: Host: Clear random address field in bt_dev in bt_disable()

This commit clears cached random address in bt_dev when calling
bt_disable(). This change makes future calls of set_random_address()
function possible with previously used address value, after BLE stack
re-initialization. Without this change no HCI command was sent, see this
condition in set_random_address():

/* Do nothing if we already have the right address */
if (!bt_addr_cmp(addr, &bt_dev.random_addr.a)) {
	return 0;
}

Signed-off-by: Adam Augustyn <[email protected]>
Signed-off-by: Herman Berget <[email protected]>
(cherry picked from commit e82fb9b)

Author: Adam Augustyn

subsys/bluetooth/host/hci_core.c

@@ -3765,6 +3765,9 @@ int bt_disable(void)
 	/* Some functions rely on checking this bitfield */
 	memset(bt_dev.supported_commands, 0x00, sizeof(bt_dev.supported_commands));
 
+	/* If random address was set up - clear it */
+	bt_addr_le_copy(&bt_dev.random_addr, BT_ADDR_LE_ANY);
+
 	/* Abort TX thread */
 	k_thread_abort(&tx_thread_data);