Bluetooth: Add bt_att_send API

This adds bt_att_send which will be used by GATT client API to send
requests.

Note: bt_att_send can only handle one request at time but once the
requirements are clarified it will probably be extended to support
more requests to attend multiple applications probably using a fifo.

Change-Id: If9e89f7f6f0d3827a7f11c8feb4f1f1045d800be
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2 files changed