Add support for SocketAttributes interface

Tested:

1) Network services bmcweb and phosphor-ipmi-net implement the interface
   xyz.openbmc_project.Control.Service.SocketAttributes and property Port
   is populated correctly.
2) Verified services like VUART does not implement the SocketAttributes interface.
3) Modified the Port of phosphor-ipmi-net and verified.
3a) Network IPMI works on the new port.
3b) The new port is reflected when quering the IPMI protocol details via Redfish.

Signed-off-by: Tom Joseph <tomjoseph@in.ibm.com>
Change-Id: I4511ce9e5426d99895f8074617cdb41d6085fd13
2 files changed