Upgrade the examples to a recent version of riscv.

[AlexisTM]

Bump all libraries to the latest version, including the regenerated version of k210-pac.

This depends on: https://github.com/riscv-rust/k210-pac/pull/39

This has been tested with the blinky example on a MaixPy board with success.

I will update the k210-crates repo once both PRs are merged, to avoid dangling submodules (like the state it currently is in)