Create library for System Interface Commands.

There are IPMI commands like Read Event Message Buffer, Set BMC Global
Enables and Get Message Flags which is to be executed from host
interface only. So creating a separate library for these commands which
would be used only by phosphor-host-ipmid.

Change-Id: I14cb4019b9ab19c84e463e5a7820010f57f1c5eb
Signed-off-by: Tom Joseph <tomjoseph@in.ibm.com>
5 files changed