rust: move dependencies to rust/Cargo.toml

As more crates start using the same dependencies, it's better to not
repeat the versions and move the dependency declarations to the workspace.

Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2 files changed