perf/arm-smmuv3: Assign parents for event_source device

Currently the PMU device appears directly under /sys/devices/
Only root busses should appear there, so instead assign the pmu->dev
parent to be the platform device.

Link: https://lore.kernel.org/linux-cxl/ZCLI9A40PJsyqAmq@kroah.com/Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240412161057.14099-23-Jonathan.Cameron@huawei.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/perf/arm_smmuv3_pmu.c

@@ -860,6 +860,7 @@ static int smmu_pmu_probe(struct platform_device *pdev)
 
 	smmu_pmu->pmu = (struct pmu) {
 		.module		= THIS_MODULE,
+		.parent		= &pdev->dev,
 		.task_ctx_nr    = perf_invalid_context,
 		.pmu_enable	= smmu_pmu_enable,
 		.pmu_disable	= smmu_pmu_disable,