Support Raspberry RP2040 target?

[overheat]

For example: https://github.com/embassy-rs/cyw43/tree/master/firmware this repo.

$ cargo call-stack --example rpi-pico-w --target RP2040 > cg.dot
error: failed to run `rustc` to learn about target-specific information

Caused by:
  process didn't exit successfully: `/home/aaron/.cargo/bin/cargo-call-stack rustc - --crate-name ___ --print=file-names --target RP2040 --crate-type bin --crate-type rlib --crate-type dylib --crate-type cdylib --crate-type staticlib --crate-type proc-macro --print=sysroot --print=cfg` (exit status: 1)
  --- stderr
  error: Error loading target specification: Could not find specification for target "RP2040". Run `rustc --print target-list` for a list of built-in targets

[Dirbaio]

That's the Rust target, not the probe-rs target. Try --target thumbv6m-none-eabi