cxl/mem: Trace General Media Event Record

CXL rev 3.0 section 8.2.9.2.1.1 defines the General Media Event Record.

Determine if the event read is a general media record and if so trace
the record as a General Media Event Record.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/r/20221216-cxl-ev-log-v7-3-2316a5c8f7d8@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>