smbios: Support for detecting system inventory path dynamically

Current support to provide inventory path suffix does not work for
platforms with systems on different boards. Add support to find paths
based on the xyz.openbmc_project.Inventory.Item.System interface.

Tested: Manually loaded on platform with and without systems on
        different boards and verified.
Fusion-Link: fusion2/NA
Google-Bug-Id: 399791928
Change-Id: Ibf3a2e969f7ce411501bb6ffe1967da2ba807d4b
Signed-off-by: Vivekanand Veeracholan <vveerach@google.com>