Bluetooth: Implement the first SMP commands

These simple commands will allow the SMP procedure to be started
and terminated with a not supported error. This is the first step
toward something useful.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Anderson Briglia <anderson.briglia@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>