Revert "x86: remove the kernel code/data/bss resources from /proc/iomem"

Revert "x86: remove the kernel code/data/bss resources from /proc/iomem"

This reverts commit 17db9a4b4a5965a6e8bafcfb9b48d289f805ffa6.

Sadly, my hope that nobody would actually use the special kernel entries
in /proc/iomem were dashed by kexec.  Which reads /proc/iomem explicitly
to find the kernel base address.  Nasty.

Anyway, that means we can't do the sane and simple thing and just remove
the entries, and we'll instead have to mask them out based on permissions.

Reported-by: Zhengyu Zhang <zhezhang@redhat.com>
Reported-by: Dave Young <dyoung@redhat.com>
Reported-by: Freeman Zhang <freeman.zhang1992@gmail.com>
Reported-by: Emrah Demir <ed@abdsec.com>
Reported-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>