Make interrupt module more standard.

- Move typelevel interrupts to a special-purpose mod: `embassy_xx::interrupt::typelevel`.
- Reexport the PAC interrupt enum in `embassy_xx::interrupt`.

This has a few advantages:
- The `embassy_xx::interrupt` module is now more "standard".
  - It works with `cortex-m` functions for manipulating interrupts, for example.
  - It works with RTIC.
- the interrupt enum allows holding value that can be "any interrupt at runtime", this can't be done with typelevel irqs.
- When "const-generics on enums" is stable, we can remove the typelevel interrupts without disruptive changes to `embassy_xx::interrupt`.

embassy-stm32/src/dma/bdma.rs

@@ -14,7 +14,7 @@ use super::ringbuffer::{DmaCtrl, DmaRingBuffer, OverrunError};
 use super::word::{Word, WordSize};
 use super::Dir;
 use crate::_generated::BDMA_CHANNEL_COUNT;
-use crate::interrupt::Interrupt;
+use crate::interrupt::typelevel::Interrupt;
 use crate::pac;
 use crate::pac::bdma::{regs, vals};
 
@@ -70,8 +70,8 @@ static STATE: State = State::new();
 pub(crate) unsafe fn init(irq_priority: Priority) {
     foreach_interrupt! {
         ($peri:ident, bdma, $block:ident, $signal_name:ident, $irq:ident) => {
-            crate::interrupt::$irq::set_priority(irq_priority);
-            crate::interrupt::$irq::enable();
+            crate::interrupt::typelevel::$irq::set_priority(irq_priority);
+            crate::interrupt::typelevel::$irq::enable();
         };
     }
     crate::_generated::init_bdma();

embassy-stm32/src/dma/dma.rs

@@ -13,7 +13,7 @@ use super::ringbuffer::{DmaCtrl, DmaRingBuffer, OverrunError};
 use super::word::{Word, WordSize};
 use super::Dir;
 use crate::_generated::DMA_CHANNEL_COUNT;
-use crate::interrupt::Interrupt;
+use crate::interrupt::typelevel::Interrupt;
 use crate::pac::dma::{regs, vals};
 use crate::{interrupt, pac};
 
@@ -149,8 +149,8 @@ static STATE: State = State::new();
 pub(crate) unsafe fn init(irq_priority: Priority) {
     foreach_interrupt! {
         ($peri:ident, dma, $block:ident, $signal_name:ident, $irq:ident) => {
-            interrupt::$irq::set_priority(irq_priority);
-            interrupt::$irq::enable();
+            interrupt::typelevel::$irq::set_priority(irq_priority);
+            interrupt::typelevel::$irq::enable();
         };
     }
     crate::_generated::init_dma();

embassy-stm32/src/dma/gpdma.rs

@@ -56,8 +56,8 @@ static STATE: State = State::new();
 pub(crate) unsafe fn init(irq_priority: Priority) {
     foreach_interrupt! {
         ($peri:ident, gpdma, $block:ident, $signal_name:ident, $irq:ident) => {
-            crate::interrupt::$irq::set_priority(irq_priority);
-            crate::interrupt::$irq::enable();
+            crate::interrupt::typelevel::$irq::set_priority(irq_priority);
+            crate::interrupt::typelevel::$irq::enable();
         };
     }
     crate::_generated::init_gpdma();