OMAP4: DMTIMER: enable autoidle mode

Currently autoidle is only enabled for OMAP2/3; by enabling autoidle,
the automatic L4 clock gating strategy is applied based on L4 activity,
otherwise L4 clock to module will be a free running.
Signed-off-by: Ambresh K <ambresh@ti.com>
[tony@atomide.com: updated for timer init changes]
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/plat-omap/dmtimer.c

@@ -209,8 +209,8 @@ static void omap_dm_timer_reset(struct omap_dm_timer *timer)
 	}
 	omap_dm_timer_set_source(timer, OMAP_TIMER_SRC_32_KHZ);
 
-	/* Enable autoidle on OMAP2 / OMAP3 */
-	if (cpu_is_omap24xx() || cpu_is_omap34xx())
+	/* Enable autoidle on OMAP2+ */
+	if (cpu_class_is_omap2())
 		autoidle = 1;
 
 	/*