BZ2026308 - Update Note for RT kernel support

This is the 2nd commit message:

Author: Stephen Smith

modules/cnf-provisioning-real-time-and-low-latency-workloads.adoc

@@ -15,7 +15,7 @@ The cluster administrator can use this performance profile configuration to make
 
 [NOTE]
 ====
-The RT kernel is only supported on worker nodes.
+In most deployments, kernel-rt is supported only on worker nodes when you use a standard cluster with three control plane nodes and three worker nodes. There are exceptions for compact and single nodes on {product-title} deployments. For installations on a single node, kernel-rt is supported on the single control plane node.
 ====
 
 To fully utilize the real-time mode, the containers must run with elevated privileges.