omap: timer: Set dmtimer used as clocksource in autoreload mode

If CONFIG_OMAP_32K_TIMER is not selected and dmtimer is used as clocksource, the
timer stops counting once overflow occurs as it was not set in autoreload mode.
This results into timekeeping failure: for example, 'sleep 1' at the shell after
the timer counter overflow would hang.

This patch sets up autoreload when starting the clocksource timer which fixes
the above issue.
Signed-off-by: NHemant Pedanekar <hemantp@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/timer.c

@@ -293,7 +293,8 @@ static void __init omap2_gp_clocksource_init(int gptimer_id,
 	pr_info("OMAP clocksource: GPTIMER%d at %lu Hz\n",
 		gptimer_id, clksrc.rate);
 
-	__omap_dm_timer_load_start(clksrc.io_base, OMAP_TIMER_CTRL_ST, 0, 1);
+	__omap_dm_timer_load_start(clksrc.io_base,
+			OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0, 1);
 	init_sched_clock(&cd, dmtimer_update_sched_clock, 32, clksrc.rate);
 
 	if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))