Fix some indentations in doc comments flagged by clippy in beta

[jannic]

No description provided.

[jannic]

warning: doc list item missing indentation
   --> rp2040-hal/src/sio.rs:594:9
    |
594 |     /// BASE0 and an upper bound of BASE1.
    |         ^
    |
    = help: if this is supposed to be its own paragraph, add a blank line
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#doc_lazy_continuation
    = note: `#[warn(clippy::doc_lazy_continuation)]` on by default
help: indent this line
    |
594 |     ///   BASE0 and an upper bound of BASE1.
    |         ++

etc.