bus: inline getters
bus: inline getters

To avoid multiple definitions in client applications.

Change-Id: I94a25217d10ffcdc04b1ef86c20863d15620875a
Signed-off-by: Brad Bishop <713d098c0be4c8fd2bf36a94cd08699466677ecd@fuzziesquirrel.com>

openbmc/sdbusplus,openbmc/sdbusplus,openbmc/sdbusplus,openbmc/sdbusplus