Add TPM Event Log IPMI Blob

This blob will read the TPM event log file,
which will be written by the client (securityd)
at "/run/tpm/tpm_event_log".

This blob does not support writes.

Tested: added unit test

Change-Id: I8d004c7290962d178c220f97f9fa9cbc89832f0d
Signed-off-by: Ana Mendes <anamendes@google.com>
Google-Bug-Id: 473854791
6 files changed