mm: add pcp high_min high_max to proc zoneinfo

When we do not set percpu_pagelist_high_fraction the kernel will compute
the pcp high_min/max by itself, which makes it hard to determine the
current high_min/max values.

So output the pcp high_min/max values to /proc/zoneinfo.

Link: https://lkml.kernel.org/r/20241010120935.656619-1-mengensun@tencent.com


Signed-off-by: MengEn Sun <mengensun@tencent.com>
Reviewed-by: Jinliang Zheng <alexjlzheng@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>