Store the last action time in session info
Store the last action time in session info

Add a timestamp member in SessionStat to capture when the session
sees activity last, and update it with every action. The timestamp
will be used to check when the session should expire.

Signed-off-by: Kun Yi <1f1e6c84c8d73059e2ad4603a830c197526c9da4@gmail.com>
Change-Id: Ic781d54173099bff76b3c37dd296521680fe7986

openbmc/phosphor-ipmi-blobs