This adds initial support for BIS/BIG which includes:

== Broadcaster role: Setup a periodic advertising and create a BIG ==

> tools/isotest -s 00:00:00:00:00:00
isotest[63]: Connected [00:00:00:00:00:00]
isotest[63]: QoS BIG 0x00 BIS 0x00 Packing 0x00 Framing 0x00]
isotest[63]: Output QoS [Interval 10000 us Latency 10 ms SDU 40 PHY 0x02
RTN 2]
isotest[63]: Sending ...
isotest[63]: Number of packets: 1
isotest[63]: Socket jitter buffer: 80 buffer
< HCI Command: LE Set Perio.. (0x08|0x003e) plen 7
...
> HCI Event: Command Complete (0x0e) plen 4
      LE Set Periodic Advertising Parameters (0x08|0x003e) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Perio.. (0x08|0x003f) plen 7
...
> HCI Event: Command Complete (0x0e) plen 4
      LE Set Periodic Advertising Data (0x08|0x003f) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Perio.. (0x08|0x0040) plen 2
...
> HCI Event: Command Complete (0x0e) plen 4
      LE Set Periodic Advertising Enable (0x08|0x0040) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Create B.. (0x08|0x0068) plen 31
...
> 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 21
      LE Broadcast Isochronous Group Complete (0x1b)
      ...

== Broadcast Receiver role: Create a PA Sync and BIG Sync ==

> tools/isotest -i hci1 -d 00:AA:01:00:00:00
isotest[66]: Waiting for connection 00:AA:01:00:00:00...
< HCI Command: LE Periodic Advert.. (0x08|0x0044) plen 14
...
> HCI Event: Command Status (0x0f) plen 4
      LE Periodic Advertising Create Sync (0x08|0x0044) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Extended Sca.. (0x08|0x0041) plen 8
...
> HCI Event: Command Complete (0x0e) plen 4
      LE Set Extended Scan Parameters (0x08|0x0041) ncmd 1
        Status: Success (0x00)
< HCI Command: LE Set Extended Sca.. (0x08|0x0042) plen 6
...
> HCI Event: Command Complete (0x0e) plen 4
      LE Set Extended Scan Enable (0x08|0x0042) ncmd 1
        Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 29
      LE Extended Advertising Report (0x0d)
      ...
> HCI Event: LE Meta Event (0x3e) plen 16
      LE Periodic Advertising Sync Established (0x0e)
      ...
< HCI Command: LE Broadcast Isoch.. (0x08|0x006b) plen 25
...
> HCI Event: Command Status (0x0f) plen 4
      LE Broadcast Isochronous Group Create Sync (0x08|0x006b) ncmd 1
        Status: Success (0x00)
> HCI Event: LE Meta Event (0x3e) plen 17
      LE Broadcast Isochronous Group Sync Estabilished (0x1d)
      ...

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Both dev_name and short_name are not guaranteed to be NULL terminated so
this instead use strnlen and then attempt to determine if the resulting
string needs to be truncated or not.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=216018
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This adds helpers for accessing and appending service data (0x16) ad
type.

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

This moves functions manipulating EIR/Adv Data to its own file so it
can be reused by other files.

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