rp: Update changelog for embassy-rp 0.4.0 release

Author: 9names

embassy-rp/CHANGELOG.md

@@ -7,12 +7,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+## 0.4.0 - 2025-03-09
+
 - Add PIO functions. ([#3857](https://github.com/embassy-rs/embassy/pull/3857))  
   The functions added in this change are `get_addr` `get_tx_threshold`, `set_tx_threshold`, `get_rx_threshold`, `set_rx_threshold`, `set_thresholds`.
 - Expose the watchdog reset reason. ([#3877](https://github.com/embassy-rs/embassy/pull/3877))
 - Update pio-rs, reexport, move instr methods to SM. ([#3865](https://github.com/embassy-rs/embassy/pull/3865))
 - rp235x: add ImageDef features. ([#3890](https://github.com/embassy-rs/embassy/pull/3890))
 - doc: Fix "the the" ([#3903](https://github.com/embassy-rs/embassy/pull/3903))
+- pio: Add access to DMA engine byte swapping ([#3935](https://github.com/embassy-rs/embassy/pull/3935))
 
 ## 0.3.1 - 2025-02-06