ARM: iop: update clock source registration

In d7e81c26 (clocksource: Add clocksource_register_hz/khz interface) new
interfaces were added which simplify (and optimize) the selection of the
divisor shift/mult constants.  Switch over to using this new interface.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/plat-iop/time.c

@@ -170,7 +170,5 @@ void __init iop_init_time(unsigned long tick_rate)
 	write_trr1(0xffffffff);
 	write_tcr1(0xffffffff);
 	write_tmr1(timer_ctl);
-	clocksource_calc_mult_shift(&iop_clocksource, tick_rate,
-				    IOP_MIN_RANGE);
-	clocksource_register(&iop_clocksource);
+	clocksource_register_hz(&iop_clocksource, tick_rate);
 }