cxl/mem: Add kdoc param for event log driver state

This makes the kernel-doc for cxl_dev_state complete.
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Link: https://lore.kernel.org/r/20230216192426.1184606-1-alison.schofield@intel.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/cxlmem.h

@@ -257,6 +257,7 @@ struct cxl_event_state {
  * @info: Cached DVSEC information about the device.
  * @serial: PCIe Device Serial Number
  * @doe_mbs: PCI DOE mailbox array
+ * @event: event log driver state
  * @mbox_send: @dev specific transport for transmitting mailbox commands
  *
  * See section 8.2.9.5.2 Capacity Configuration and Label Storage for