perf/riscv: 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 appropriate platform devices.

Link: https://lore.kernel.org/linux-cxl/ZCLI9A40PJsyqAmq@kroah.com/
Cc: Atish Patra <atishp@atishpatra.org>
CC: Anup Patel <anup@brainfault.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240412161057.14099-13-Jonathan.Cameron@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

Author: jic23

drivers/perf/riscv_pmu_legacy.c

@@ -136,6 +136,7 @@ static int pmu_legacy_device_probe(struct platform_device *pdev)
 	pmu = riscv_pmu_alloc();
 	if (!pmu)
 		return -ENOMEM;
+	pmu->pmu.parent = &pdev->dev;
 	pmu_legacy_init(pmu);
 
 	return 0;

drivers/perf/riscv_pmu_sbi.c

@@ -1080,6 +1080,7 @@ static int pmu_sbi_device_probe(struct platform_device *pdev)
 	}
 
 	pmu->pmu.attr_groups = riscv_pmu_attr_groups;
+	pmu->pmu.parent = &pdev->dev;
 	pmu->cmask = cmask;
 	pmu->ctr_start = pmu_sbi_ctr_start;
 	pmu->ctr_stop = pmu_sbi_ctr_stop;