x86: Use generic posix_types.h

Change the x86 architecture to use <asm-generic/posix_types.h>.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1328677745-20121-20-git-send-email-hpa@zytor.com
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>