sparc/perf: Remove driver-specific throttle support

The throttle support has been added in the generic code. Remove
the driver-specific throttle support.

Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250520181644.2673067-15-kan.liang@linux.intel.com

Author: Kan Liang

arch/sparc/kernel/perf_event.c

@@ -1668,8 +1668,7 @@ static int __kprobes perf_event_nmi_handler(struct notifier_block *self,
 		if (!sparc_perf_event_set_period(event, hwc, idx))
 			continue;
 
-		if (perf_event_overflow(event, &data, regs))
-			sparc_pmu_stop(event, 0);
+		perf_event_overflow(event, &data, regs);
 	}
 
 	finish_clock = sched_clock();