Jeff Chua reported that:

Commit e40c0fe6
(x86: cleanup duplicate includes) turned the userspace
asm-x86/posix_types.h and asm-x86/unistd.h headers into
empty files.

This patch reverts these bogus changes.
Reported-by: NJeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>