tlcl: add implementations for GetOwnership and Read/WriteLock

mount-encrypted needs to be aware of TPM ownership status, and
will also want to issue a read lock for the early access NVRAM
index.

BRANCH=none
BUG=chromium:625037
TEST=mount-encrypted shows ownership at boot with kevin

Change-Id: I42f43f91d892137e1c46c7cacd88e3b749ce7f04
Reviewed-on: https://chromium-review.googlesource.com/366443
Commit-Ready: Andrey Pronin <apronin@chromium.org>
Tested-by: Stephen Barber <smbarber@chromium.org>
Reviewed-by: Andrey Pronin <apronin@chromium.org>
3 files changed