clockevents/drivers/dummy_timer: Migrate to new 'set-state' interface

Migrate dummy_timer driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

We weren't doing anything in the ->set_mode() callback. So, this patch
doesn't provide any set-state callbacks.

Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Viresh Kumae <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/clocksource/dummy_timer.c

@@ -16,15 +16,6 @@
 
 static DEFINE_PER_CPU(struct clock_event_device, dummy_timer_evt);
 
-static void dummy_timer_set_mode(enum clock_event_mode mode,
-			   struct clock_event_device *evt)
-{
-	/*
-	 * Core clockevents code will call this when exchanging timer devices.
-	 * We don't need to do anything here.
-	 */
-}
-
 static void dummy_timer_setup(void)
 {
 	int cpu = smp_processor_id();
@@ -35,7 +26,6 @@ static void dummy_timer_setup(void)
 			  CLOCK_EVT_FEAT_ONESHOT |
 			  CLOCK_EVT_FEAT_DUMMY;
 	evt->rating	= 100;
-	evt->set_mode	= dummy_timer_set_mode;
 	evt->cpumask	= cpumask_of(cpu);
 
 	clockevents_register_device(evt);