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.com


Signed-off-by: Dan Williams <dan.j.williams@intel.com>