to #26424368

This introduces the new bool kconfig MEMSLI, determining whether the
memsli (memory latency histogram) feature should be built-in or not.
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>