BUG about Hisilicon PMU

[Zhengyuan Liu]

Hi, all

When boot v5.11-rc2 on my Kunpeng 920 PC, the kernel will block at PMU
initialization stage, and after binary-search with bisect I found that
this problem was introduced by commit ac4511c9364c ("drivers/perf:
hisi: Add identifier sysfs file"),
and to be more accurate it actually blocked at following position:

    hisi_hha_pmu_init_data():
         hha_pmu->identifier = readl(hha_pmu->base + HHA_VERSION);

If you guys had already know this problem, please ignore this message.

Thanks,