i386: Add warning in Documentation that zero-page is not a stable ABI
i386: Add warning in Documentation that zero-page is not a stable ABI

Some people writing boot loaders seem to falsely belief the 32bit zero page is a
stable interface for out of tree code like the real mode boot protocol. Add a comment
clarifying that is not true.

Signed-off-by: Andi Kleen <0474aee45985f5ae829f53849df476200e876990@suse.de>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs