perf/thunderx2: Assign parents for event_source devices

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

Link: https://lore.kernel.org/linux-cxl/ZCLI9A40PJsyqAmq@kroah.com/
Cc: Robert Richter <rric@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240412161057.14099-12-Jonathan.Cameron@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

Author: jic23

drivers/perf/thunderx2_pmu.c

@@ -724,6 +724,7 @@ static int tx2_uncore_pmu_register(
 	/* Perf event registration */
 	tx2_pmu->pmu = (struct pmu) {
 		.module         = THIS_MODULE,
+		.parent		= tx2_pmu->dev,
 		.attr_groups	= tx2_pmu->attr_groups,
 		.task_ctx_nr	= perf_invalid_context,
 		.event_init	= tx2_uncore_event_init,