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

Let's see if anybody even notices.  I doubt anybody uses this, and it
does expose addresses that should be randomized, so let's just remove
the code.  It's old and traditional, and it used to be cute, but we
should have removed this long ago.

If it turns out anybody notices and this breaks something, we'll have to
revert this, and maybe we'll end up using other approaches instead
(using %pK or similar).  But removing unnecessary code is always the
preferred option.

Noted-by: Emrah Demir <ed@abdsec.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>