ia64: Fix __delay() to do The Right Thing. In practice, this may

ia64: Fix __delay() to do The Right Thing.  In practice, this may
	cause BogoMIPS to drop to half the clock-speed with current
	versions of GCC, but this just shows that GCC doesn't generate
	very good code for single-cycle loops.  Perhaps it will motivate
	someone to improve GCC in this area (though it's hardly of
	practical value, other than for producing large BogoMIPS values).