Bluetooth: Implement disable and removal of adv instance

If ext adv is enabled then use ext adv to disable as well.
Also remove the adv set during LE disable.

< HCI Command: LE Set Extended Advertising Enable (0x08|0x0039) plen 2
        Extended advertising: Disabled (0x00)
        Number of sets: Disable all sets (0x00)
> HCI Event: Command Complete (0x0e) plen 4
      LE Set Extended Advertising Enable (0x08|0x0039) ncmd 2
        Status: Success (0x00)

Signed-off-by: Jaganath Kanakkassery <jaganathx.kanakkassery@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>