control: Use `poweron_target` in place of `full_speed`

The use of `full_speed` as a zone configuration attribute is removed in
favor of `poweron_target`.

Change-Id: I1edb03f2c738105479d1ddf1236880aa28e667f3
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
diff --git a/control/json/zone.cpp b/control/json/zone.cpp
index e09ee61..fa4e269 100644
--- a/control/json/zone.cpp
+++ b/control/json/zone.cpp
@@ -267,21 +267,14 @@
 
 void Zone::setPowerOnTarget(const json& jsonObj)
 {
-    // TODO Remove "full_speed" after configs replaced with "poweron_target"
-    if (!jsonObj.contains("full_speed") && !jsonObj.contains("poweron_target"))
+    if (!jsonObj.contains("poweron_target"))
     {
         auto msg = "Missing required zone's poweron target";
         log<level::ERR>(msg, entry("JSON=%s", jsonObj.dump().c_str()));
         throw std::runtime_error(msg);
     }
-    if (jsonObj.contains("full_speed"))
-    {
-        _poweronTarget = jsonObj["full_speed"].get<uint64_t>();
-    }
-    else
-    {
-        _poweronTarget = jsonObj["poweron_target"].get<uint64_t>();
-    }
+    _poweronTarget = jsonObj["poweron_target"].get<uint64_t>();
+
     // Start with the current target set as the poweron target
     _target = _poweronTarget;
 }