perf/arm-dmc620: 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/20240412161057.14099-21-Jonathan.Cameron@huawei.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/perf/arm_dmc620_pmu.c

@@ -673,6 +673,7 @@ static int dmc620_pmu_device_probe(struct platform_device *pdev)
 
 	dmc620_pmu->pmu = (struct pmu) {
 		.module = THIS_MODULE,
+		.parent		= &pdev->dev,
 		.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
 		.task_ctx_nr	= perf_invalid_context,
 		.event_init	= dmc620_pmu_event_init,