drivers/perf: hisi: Export associated CPUs of each PMU through sysfs

drivers/perf: hisi: Export associated CPUs of each PMU through sysfs

Although the event of the uncore PMU can only be opened on a single
CPU, some PMU does have the affinity on a range of CPUs. For example
the L3C PMU is associated to the CPUs sharing the L3T it monitors.
Users may infer this affinity by the PMU name which may have SCCL ID
and CCL ID encoded (for L3C etc), but it's not that straightforward.
So export this information by adding an "associated_cpus" sysfs
attribute then user can get this directly.

Reviewed-by: Jonathan Cameron <Joanthan.Cameron@huawei.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20241210141525.37788-9-yangyicong@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>