With the mem_events, perf doesn't need to read sysfs for each PMU to
find the mem-events-supported PMU. The patch also makes it possible to
clean up the related __weak functions later.

The patch is only to add the mem_events into the perf_pmu for all ARCHs.
It will be used in the later cleanup patches.
Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: Kajol Jain <kjain@linux.ibm.com>
Tested-by: Ravi Bangoria <ravi.bangoria@amd.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Kajol Jain <kjain@linux.ibm.com>
Suggested-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: will@kernel.org
Cc: mike.leach@linaro.org
Cc: renyu.zj@linux.alibaba.com
Cc: yuhaixin.yhx@linux.alibaba.com
Cc: tmricht@linux.ibm.com
Cc: atrajeev@linux.vnet.ibm.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: john.g.garry@oracle.com
Link: https://lore.kernel.org/r/20240123185036.3461837-2-kan.liang@linux.intel.comSigned-off-by: Namhyung Kim <namhyung@kernel.org>