arm: kernel: utilize hrtimer based broadcast

Hrtimer based broadcast is used on ARM platform. It can be
registered as the tick broadcast device in the absence of
a real external clock device.

Signed-off-by: Alison Wang <alison.wang@freescale.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>

arch/arm/kernel/time.c

@@ -9,6 +9,7 @@
  *  reading the RTC at bootup, etc...
  */
 #include <linux/clk-provider.h>
+#include <linux/clockchips.h>
 #include <linux/clocksource.h>
 #include <linux/errno.h>
 #include <linux/export.h>
@@ -107,5 +108,7 @@ void __init time_init(void)
 		of_clk_init(NULL);
 #endif
 		timer_probe();
+
+		tick_setup_hrtimer_broadcast();
 	}
 }