1845 allow disable of UNMAP via stmfadm(1M).

@@ -65,10 +65,12 @@
         char        rev[4];
         boolean_t   writeProtectEnableValid;
         boolean_t   writeProtectEnable;
         boolean_t   writebackCacheDisableValid;
         boolean_t   writebackCacheDisable;
+        boolean_t   unmapValid;
+        boolean_t   unmap;
         uint16_t    accessState;
         uint32_t    hostId;
         boolean_t   hostIdValid;
 } diskResource;