Add riscv64 to outputs list in release-process.md
Add riscv64 to outputs list in release-process.md

The riscv64 binary is created by the Gitian scripts and distributed by the
Bitcoin Core website, so it should be listed in the release process docs.


Former-commit-id: ae11e0918bb1423cb048e3cc1355ec88ee6166d1
syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin