Blackfin: drop duplicate sched_clock

The Blackfin sched_clock() func is pretty much a duplicate of the common
version, so just punt it.
Reported-by: NDavid Miller <davem@davemloft.net>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>

arch/blackfin/kernel/time.c

@@ -184,11 +184,3 @@ void __init time_init(void)
 
 	time_sched_init(timer_interrupt);
 }
-
-/*
- * Scheduler clock - returns current time in nanosec units.
- */
-unsigned long long sched_clock(void)
-{
-	return (unsigned long long)jiffies *(NSEC_PER_SEC / HZ);
-}