embassy: Refactor module structure to remove kitchen-sink util.

embassy-nrf/src/uarte.rs

@@ -8,7 +8,8 @@ use core::sync::atomic::{compiler_fence, Ordering};
 use core::task::Poll;
 use embassy::interrupt::InterruptExt;
 use embassy::traits::uart::{Error, Read, ReadUntilIdle, Write};
-use embassy::util::{AtomicWaker, OnDrop, Unborrow};
+use embassy::util::Unborrow;
+use embassy_hal_common::drop::OnDrop;
 use embassy_hal_common::unborrow;
 use futures::future::poll_fn;
 
@@ -439,6 +440,8 @@ impl<'d, U: Instance, T: TimerInstance> Write for UarteWithIdle<'d, U, T> {
 }
 
 pub(crate) mod sealed {
+    use embassy::waitqueue::AtomicWaker;
+
     use super::*;
 
     pub struct State {