[PATCH] x86: sys_ioperm() prototype cleanup

- there's no reason for duplicating the prototype from
  include/linux/syscalls.h in include/asm-x86_64/unistd.h
- every file should #include the headers containing the prototypes for
  it's global functions

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andi Kleen <ak@suse.de>