ARM: at91: PIT: Use DIV_ROUND_CLOSEST to compute the cycles

Until now, the pit_cycle computation was dividing the rate by HZ, rounding to
the closest integer, but without using the appropriate macro.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

arch/arm/mach-at91/at91sam926x_time.c

@@ -252,7 +252,7 @@ void __init at91sam926x_pit_init(void)
 	if (IS_ERR(mck))
 		panic("AT91: PIT: Unable to get mck clk\n");
 	pit_rate = clk_get_rate(mck) / 16;
-	pit_cycle = (pit_rate + HZ/2) / HZ;
+	pit_cycle = DIV_ROUND_CLOSEST(pit_rate, HZ);
 	WARN_ON(((pit_cycle - 1) & ~AT91_PIT_PIV) != 0);
 
 	/* Initialize and enable the timer */