perf/x86/amd: 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>
Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20250520181644.2673067-5-kan.liang@linux.intel.com

Author: Kan Liang

arch/x86/events/amd/core.c

@@ -1003,8 +1003,7 @@ static int amd_pmu_v2_handle_irq(struct pt_regs *regs)
 
 		perf_sample_save_brstack(&data, event, &cpuc->lbr_stack, NULL);
 
-		if (perf_event_overflow(event, &data, regs))
-			x86_pmu_stop(event, 0);
+		perf_event_overflow(event, &data, regs);
 	}
 
 	/*

arch/x86/events/amd/ibs.c

@@ -1373,9 +1373,7 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs)
 		hwc->sample_period = perf_ibs->min_period;
 
 out:
-	if (throttle) {
-		perf_ibs_stop(event, 0);
-	} else {
+	if (!throttle) {
 		if (perf_ibs == &perf_ibs_op) {
 			if (ibs_caps & IBS_CAPS_OPCNTEXT) {
 				new_config = period & IBS_OP_MAX_CNT_EXT_MASK;