ARM: ux500: Don't attempt to enable the Nomadik System Timer twice

When booting with DT enabled we already call clocksource_of_init(),
which in turn calls the OF version of nmdk_timer_init().
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/mach-ux500/timer.c

@@ -97,8 +97,8 @@ void __init ux500_timer_init(void)
 	 * sched_clock with higher rating then MTU since is always-on.
 	 *
 	 */
-
-	nmdk_timer_init(mtu_timer_base, IRQ_MTU0);
+	if (!of_have_populated_dt())
+		nmdk_timer_init(mtu_timer_base, IRQ_MTU0);
 	clksrc_dbx500_prcmu_init(prcmu_timer_base);
 	ux500_twd_init();
 }