Blackfin: implement ndelay()

#define	HZSCALE		(268435456 / (1000000/HZ))

static inline void udelay(unsigned long usecs)

static inline unsigned long __to_delay(unsigned long scale)

{

	extern unsigned long loops_per_jiffy;

	__delay((((usecs * HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6);

	return (((scale * HZSCALE) >> 11) * (loops_per_jiffy >> 11)) >> 6;

}

static inline void udelay(unsigned long usecs)

{

	__delay(__to_delay(usecs));

}

static inline void ndelay(unsigned long nsecs)

{

	__delay(__to_delay(1) * nsecs / 1000);

}

#define ndelay ndelay

#endif