ARM: OMAP: avoid build wdt platform device if with dt support

If provided dt support, then skip add wdt platform device as usual.
Signed-off-by: NXiao Jiang <jgq516@gmail.com>
Reviewed-by: NJon Hunter <jon-hunter@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/devices.c

@@ -772,7 +772,7 @@ static int __init omap_init_wdt(void)
 	char *oh_name = "wd_timer2";
 	char *dev_name = "omap_wdt";
 
-	if (!cpu_class_is_omap2())
+	if (!cpu_class_is_omap2() || of_have_populated_dt())
 		return 0;
 
 	oh = omap_hwmod_lookup(oh_name);