tpm_manager: Add an implementation for TpmNvram for Tpm1.2

This CL implements the TpmNvram interface for Tpm1.2. A lot of
the implementation is adapted from tpm_impl.cc in cryptohome.

Bug: 24059574
TEST=ran nvram methods on an owned tpm1.2

Change-Id: Ica3490cff76bb087d8d26f59440ca150b6c9833d