fix(doc): prepareosd mem limit removed since rook v1.10 (#308)

Author: andy108369

providers/build-a-cloud-provider/helm-based-provider-persistent-storage-enablement/deploy-persistent-storage.md

@@ -239,10 +239,6 @@ configOverride: |
   osd_pool_default_min_size = 2
 
 cephClusterSpec:
-  resources:
-    prepareosd:
-      limits:
-        memory: "800Mi"
 
   mon:
     count: 3