control: Remove references to "speed" in JSON objects

Fan control can be configured to control any type of fan where "speed"
implies a fan control by setting RPMs. However, fans that are PWM
driven, can also be configured to be controlled so the preference would
be to not specific refer to setting "speeds".

Change-Id: Ia8920832ea29b519bf408c850febb3fed04ad3f9
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
diff --git a/control/json/group.hpp b/control/json/group.hpp
index e99687f..6b30b9f 100644
--- a/control/json/group.hpp
+++ b/control/json/group.hpp
@@ -30,7 +30,7 @@
  * A group contains a list of dbus objects that are logically grouped together
  * to be used within one-or-more configured fan control events. An event object
  * is configured to apply a set of actions against a list of groups that could
- * result in a fan control speed change. A group may also be configured against
+ * result in a fan control target change. A group may also be configured against
  * a list of profiles(OPTIONAL) and or denote a specific service(OPTIONAL) that
  * serves the list of dbus objects in the group.
  *