CCM Authentication optimization

CCM   is now optimized. Instead of being computed twice,
libtomcrypt code has been optimized so that classical ccm_init, ccm_process,...
can be used incrementally (when the whole stream is not available when
starting the authentication).
CCM way of proceeding is now very closed to GCM authentication.

Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Tested-by: Pascal Brand <pascal.brand@linaro.org>