tpm_lite: Support delegation family functionality.

Adds two new functions and their corresponding TPM commands to create
delegation families and list the delegation family table, respectively.
This isn't sufficient to meaningfully manage delegation families, but good
enough for the (ab)use case of storing flags in delegation family labels, which
we are going to do in order to strengthen encrypted stateful to guarantee
recreation of the encrypted file system after TPM clear..

BRANCH=None
BUG=chromium:788719
TEST=new unit tests

Change-Id: I31beb662784a8fff450b485c7cabc553944d7772
Reviewed-on: https://chromium-review.googlesource.com/817199
Trybot-Ready: Mattias Nissler <mnissler@chromium.org>
Tested-by: Mattias Nissler <mnissler@chromium.org>
Reviewed-by: Andrey Pronin <apronin@chromium.org>