Remove parameter from docs

Author: Robin Scherrer

docs/modules/ROOT/pages/references/parameters.adoc

@@ -46,14 +46,6 @@ default:: `15m`
 
 The interval time the System Upgrade Controller check for plan execution.
 
-== `suc_image`
-
-[horizontal]
-type:: string
-default:: `docker.io/rancher/system-upgrade-controller:v0.6.2`
-
-The System Upgrade Controller image used in the controller deployment.
-
 == `affinity`
 
 [horizontal]