cxl/memdev: Document security state in kern-doc

... as is the case with all members of struct cxl_memdev_state.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://lore.kernel.org/r/20230726051940.3570-3-dave@stgolabs.net
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>

drivers/cxl/cxlmem.h

@@ -434,6 +434,7 @@ struct cxl_dev_state {
  * @next_persistent_bytes: persistent capacity change pending device reset
  * @event: event log driver state
  * @poison: poison driver state info
+ * @security: security driver state info
  * @fw: firmware upload / activation state
  * @mbox_send: @dev specific transport for transmitting mailbox commands
  *