CHANGELOG: document TPIU::swo_supports

Author: tmplt

CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - DWT: add `configure` API for address, cycle count comparison (#342, #367).
 - ITM: add `configure` API (#342).
 - TPIU: add API for *Formatter and Flush Control* (FFCR) and *Selected Pin Control* (SPPR) registers (#342).
+- TPIU: add `swo_supports` for checking what SWO configurations the target supports. (#381)
 - Add `std` and `serde` crate features for improved host-side ITM decode functionality when working with the downstream `itm`, `cargo-rtic-scope` crates (#363, #366).
 
 ## [v0.7.4] - 2021-12-31