This patch basically replaces legacy adv with extended adv
based on the controller support. Currently there is no
design change. ie only one adv set will be enabled at a time.

This also adds tx_power in instance and store whatever returns
from Set_ext_parameter, use the same in adv data as well.
For instance 0 tx_power is stored in hdev only.

< HCI Command: LE Set Extended Advertising Parameters (0x08|0x0036) plen 25
        Handle: 0x00
        Properties: 0x0010
          Use legacy advertising PDUs: ADV_NONCONN_IND
        Min advertising interval: 1280.000 msec (0x0800)
        Max advertising interval: 1280.000 msec (0x0800)
        Channel map: 37, 38, 39 (0x07)
        Own address type: Random (0x01)
        Peer address type: Public (0x00)
        Peer address: 00:00:00:00:00:00 (OUI 00-00-00)
        Filter policy: Allow Scan Request from Any, Allow Connect Request from Any (0x00)
        TX power: 127 dbm (0x7f)
        Primary PHY: LE 1M (0x01)
        Secondary max skip: 0x00
        Secondary PHY: LE 1M (0x01)
        SID: 0x00
        Scan request notifications: Disabled (0x00)
> HCI Event: Command Complete (0x0e) plen 5
      LE Set Extended Advertising Parameters (0x08|0x0036) ncmd 1
        Status: Success (0x00)
        TX power (selected): 7 dbm (0x07)
< HCI Command: LE Set Extended Advertising Enable (0x08|0x0039) plen 6
        Extended advertising: Enabled (0x01)
        Number of sets: 1 (0x01)
        Entry 0
          Handle: 0x00
          Duration: 0 ms (0x00)
          Max ext adv events: 0
> 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>