Added note related to VMware vSphere CSI driver operator

Author: subhtk

modules/vmware-csi-driver-reqs.adoc

@@ -29,4 +29,9 @@ To install the vSphere CSI Driver Operator, the following requirements must be m
 * Virtual machines of hardware version 15 or later
 * No third-party vSphere CSI driver already installed in the cluster
 
-If a third-party vSphere CSI driver is present in the cluster, {product-title} does not overwrite it. The presence of a third-party vSphere CSI driver prevents {product-title} from upgrading to {product-title} 4.13 or later.
+If a third-party vSphere CSI driver is present in the cluster, {product-title} does not overwrite it. The presence of a third-party vSphere CSI driver prevents {product-title} from updating to {product-title} 4.13 or later.
+
+[NOTE]
+====
+The VMware vSphere CSI Driver Operator is supported only on clusters deployed with `platform: vsphere` in the installation manifest.
+====