It is required for some configurations to have multiple BISes as part
of the same BIG.

Similar to the flow implemented for unicast, DEFER_SETUP will also be
used to bind multiple BISes for the same BIG, before starting Periodic
Advertising and creating the BIG.

The user will have to open a new socket for each BIS. By setting the
BT_DEFER_SETUP socket option and calling connect, a new connection
will be added for the BIG and advertising handle set by the socket
QoS parameters. Since all BISes will be bound for the same BIG and
advertising handle, the socket QoS options and base parameters should
match for all connections.

By calling connect on a socket that does not have the BT_DEFER_SETUP
option set, periodic advertising will be started and the BIG will
be created, with a BIS for each previously bound connection. Since
a BIG cannot be reconfigured with additional BISes after creation,
no more connections can be bound for the BIG after the start periodic
advertising and create BIG commands have been queued.

The bis_cleanup function has also been updated, so that the advertising
set and the BIG will not be terminated unless there are no more
bound or connected BISes.

The HCI_CONN_BIG_CREATED connection flag has been added to indicate
that the BIG has been successfully created. This flag is checked at
bis_cleanup, so that the BIG is only terminated if the
HCI_LE_Create_BIG_Complete has been received.

This implementation has been tested on hardware, using the "isotest"
tool with an additional command line option, to specify the number of
BISes to create as part of the desired BIG:

    tools/isotest -i hci0 -s 00:00:00:00:00:00 -N 2 -G 1 -T 1

The btmon log shows that a BIG containing 2 BISes has been created:

< HCI Command: LE Create Broadcast Isochronous Group (0x08|0x0068) plen 31
        Handle: 0x01
        Advertising Handle: 0x01
        Number of BIS: 2
        SDU Interval: 10000 us (0x002710)
        Maximum SDU size: 40
        Maximum Latency: 10 ms (0x000a)
        RTN: 0x02
        PHY: LE 2M (0x02)
        Packing: Sequential (0x00)
        Framing: Unframed (0x00)
        Encryption: 0x00
        Broadcast Code: 00000000000000000000000000000000

> HCI Event: Command Status (0x0f) plen 4
      LE Create Broadcast Isochronous Group (0x08|0x0068) ncmd 1
        Status: Success (0x00)

> HCI Event: LE Meta Event (0x3e) plen 23
      LE Broadcast Isochronous Group Complete (0x1b)
        Status: Success (0x00)
        Handle: 0x01
        BIG Synchronization Delay: 1974 us (0x0007b6)
        Transport Latency: 1974 us (0x0007b6)
        PHY: LE 2M (0x02)
        NSE: 3
        BN: 1
        PTO: 1
        IRC: 3
        Maximum PDU: 40
        ISO Interval: 10.00 msec (0x0008)
        Connection Handle #0: 10
        Connection Handle #1: 11

< HCI Command: LE Setup Isochronous Data Path (0x08|0x006e) plen 13
        Handle: 10
        Data Path Direction: Input (Host to Controller) (0x00)
        Data Path: HCI (0x00)
        Coding Format: Transparent (0x03)
        Company Codec ID: Ericsson Technology Licensing (0)
        Vendor Codec ID: 0
        Controller Delay: 0 us (0x000000)
        Codec Configuration Length: 0
        Codec Configuration:

> HCI Event: Command Complete (0x0e) plen 6
      LE Setup Isochronous Data Path (0x08|0x006e) ncmd 1
        Status: Success (0x00)
        Handle: 10

< HCI Command: LE Setup Isochronous Data Path (0x08|0x006e) plen 13
        Handle: 11
        Data Path Direction: Input (Host to Controller) (0x00)
        Data Path: HCI (0x00)
        Coding Format: Transparent (0x03)
        Company Codec ID: Ericsson Technology Licensing (0)
        Vendor Codec ID: 0
        Controller Delay: 0 us (0x000000)
        Codec Configuration Length: 0
        Codec Configuration:

> HCI Event: Command Complete (0x0e) plen 6
      LE Setup Isochronous Data Path (0x08|0x006e) ncmd 1
        Status: Success (0x00)
        Handle: 11

< ISO Data TX: Handle 10 flags 0x02 dlen 44

< ISO Data TX: Handle 11 flags 0x02 dlen 44

> HCI Event: Number of Completed Packets (0x13) plen 5
        Num handles: 1
        Handle: 10
        Count: 1

> HCI Event: Number of Completed Packets (0x13) plen 5
        Num handles: 1
        Handle: 11
        Count: 1
Signed-off-by: Iulia Tanasescu <iulia.tanasescu@nxp.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>