discover-system-state: add multi-host support

Add HostObjects class to fetch paths of settings d-bus objects under
/xyz/openbmc_project/control/hostX .

Signed-off-by: Potin Lai <potin.lai@quantatw.com>
Change-Id: I1dc55ec389e94e6c85aa7031b304f8c4ed15dc71
diff --git a/settings.cpp b/settings.cpp
index ff5d36f..8146261 100644
--- a/settings.cpp
+++ b/settings.cpp
@@ -18,7 +18,7 @@
 constexpr auto mapperPath = "/xyz/openbmc_project/object_mapper";
 constexpr auto mapperIntf = "xyz.openbmc_project.ObjectMapper";
 
-Objects::Objects(sdbusplus::bus::bus& bus) : bus(bus)
+Objects::Objects(sdbusplus::bus::bus& bus, const Path& root) : bus(bus)
 {
     std::vector<std::string> settingsIntfs = {autoRebootIntf, powerRestoreIntf};
     auto depth = 0;
@@ -127,4 +127,8 @@
     return result.begin()->first;
 }
 
+HostObjects::HostObjects(sdbusplus::bus::bus& bus, size_t id) :
+    Objects(bus, Path("/xyz/openbmc_project/control/host") + std::to_string(id))
+{}
+
 } // namespace settings