Redfish: Remove BMCWEB_ENABLE_REDFISH_ONE_CHASSIS

Removed the BMCWEB_ENABLE_REDFISH_ONE_CHASSIS #define.  The new support
for finding chassis sensors via associations is now used on all systems.

Test Plan:
  https://gist.github.com/smccarney/f5b4783d8cf41a486ceff9b941b1ba9a

Tested: Verified the Chassis, Power, and Thermal output was valid on a
	Witherspoon system.  Verified sensor associations on Witherspoon
        work with bmcweb implementation.  Ran Redfish Service Validator.

Change-Id: I975f79da2c9de63e4ddd155d39ea872ca9fbffa9
Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
diff --git a/redfish-core/lib/managers.hpp b/redfish-core/lib/managers.hpp
index 65bea03..2df6034 100644
--- a/redfish-core/lib/managers.hpp
+++ b/redfish-core/lib/managers.hpp
@@ -989,11 +989,7 @@
         res.jsonValue["Links"]["ManagerForServers@odata.count"] = 1;
         res.jsonValue["Links"]["ManagerForServers"] = {
             {{"@odata.id", "/redfish/v1/Systems/system"}}};
-#ifdef BMCWEB_ENABLE_REDFISH_ONE_CHASSIS
-        res.jsonValue["Links"]["ManagerForChassis@odata.count"] = 1;
-        res.jsonValue["Links"]["ManagerForChassis"] = {
-            {{"@odata.id", "/redfish/v1/Chassis/chassis"}}};
-#endif
+
         std::shared_ptr<AsyncResp> asyncResp = std::make_shared<AsyncResp>(res);
 
         crow::connections::systemBus->async_method_call(