updating OCP version (#2353)

Author: g-murray

downstream/modules/platform/ref-operator-ocp-version.adoc

@@ -4,7 +4,7 @@
 
 [role="_abstract"]
 
-The {OperatorPlatformNameShort} to install {PlatformNameShort} {PlatformVers} is available on {OCPShort} 4.9 and later versions.
+The {OperatorPlatformNameShort} to install {PlatformNameShort} {PlatformVers} is available on {OCPShort} 4.12 through to 4.17 and later versions.
 
 [role="_additional-resources"]
 .Additional resources