Merge #112

112: Propose to release a version `riscv` v0.8.1 r=almindor a=luojia65

The `riscv` crate includes an important fix (https://github.com/rust-embedded/riscv/pull/107

) where the RustSBI community would leverage the use of. However, the latest release v0.8.0 did not include this fix. In this pull request we want to propose to release a new version of `riscv` crate to include at least this fix, so that RustSBI community would write correct implemenations based on this crate.

Notes to `CHANGELOG.md`: the release date `2022-10-06` can always be changed.

r? `@Disasm` 

Co-authored-by: luojia65 <me@luojia.cc>