perf/amlogic: 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/
Reviewed-by: Jiucheng Xu <jiucheng.xu@amlogic.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240412161057.14099-7-Jonathan.Cameron@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

Author: jic23

drivers/perf/amlogic/meson_ddr_pmu_core.c

@@ -492,6 +492,7 @@ int meson_ddr_pmu_create(struct platform_device *pdev)
 	*pmu = (struct ddr_pmu) {
 		.pmu = {
 			.module		= THIS_MODULE,
+			.parent		= &pdev->dev,
 			.capabilities	= PERF_PMU_CAP_NO_EXCLUDE,
 			.task_ctx_nr	= perf_invalid_context,
 			.attr_groups	= attr_groups,