[PATCH V3] perf vendor events riscv: add T-HEAD C9xx JSON file

[Inochi Amaoto]

> licheerv # perf record
> [  432.015618] watchdog: BUG: soft lockup - CPU#0 stuck for 26s!
> [perf:117]
> [  460.015617] watchdog: BUG: soft lockup - CPU#0 stuck for 52s!
> [perf:117]
> [  488.015616] watchdog: BUG: soft lockup - CPU#0 stuck for 78s!
> [perf:117]
> [  516.015617] watchdog: BUG: soft lockup - CPU#0 stuck for 104s!
> [perf:117]
>
> But that's not related to your patch anyway.

Same issue on c920, but it did not always occur.
Like a sbi issue for T-HEAD cpus.

> I am strongly against using "c9xx" wildcard, i would prefer declaring
> them separate (especially taking in mind that c920 is c910 with vector
> - AFAIK), but that's up to Arnaldo to decide.

AFAIK, there is no reliable way to distinguish c906 and c910 cores. And
the events of c910 and c920 are the same (according to the draft document
of the c920).

Anyway, I agree to let Arnaldo decide.

> Tested-by: Nikita Shubin <n.shubin at yadro.com>

Thanks.