v0.4.0

The package now requires imxrt-ral to represent its register access layer.
The Peripherals trait is gone, and users are expected to use imxrt-ral
peripheral instances.

The defmt feature replaces the defmt-03 feature. Activating this
package's defmt feature does not activate the similarly-named feature
in the usb-device package. You may enable them individually.

Upgrade package to Rust 2024.