[riscv64] Change one of the owners for RISCV.

Change-Id: I34d31032b8f1704ddea6334398a4ff2198cc192d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2822631Reviewed-by: Brice Dobry <brice.dobry@futurewei.com>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Commit-Queue: Brice Dobry <brice.dobry@futurewei.com>
Cr-Commit-Position: refs/heads/master@{#74069}

RISCV_OWNERS

 brice.dobry@futurewei.com
-lazyparser@gmail.com
 peng.w@rioslab.org
+qiuji@iscas.ac.cn