If we have a buffer that's larger than the supported ACL MTU we need
to split it into multiple fragments. The first fragment will have
'start' in the flags that are encoded to the connection handle and
subsequent ones will have 'continue' encoded into them.
To not loose track of the original buffer until we have created all of
the fragments we store each buffers in a temporary FIFO and then later
read them back out from there and put them into the tx_queue.
Change-Id: Ice77a79a89286829d624f76df77e0aa719af1490
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>