cxl/mbox: Add missing parameter to docs.

Kernel-doc should be complete, so add documentation for the status
parameter.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20230130153437.3153-1-Jonathan.Cameron@huawei.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/core/mbox.c

@@ -892,6 +892,7 @@ static void cxl_mem_get_records_log(struct cxl_dev_state *cxlds,
 /**
  * cxl_mem_get_event_records - Get Event Records from the device
  * @cxlds: The device data for the operation
+ * @status: Event Status register value identifying which events are available.
  *
  * Retrieve all event records available on the device, report them as trace
  * events, and clear them.