platforms/stm32f7: add reusable F722 firmware

libs/kaptan-dma/src/lib.rs

@@ -8,7 +8,7 @@
 /// A borrowed byte range prepared for a device-to-read DMA transfer.
 ///
 /// This is a capability rather than a general byte-slice wrapper. It exists
-/// only after a board-selected policy proves DMA reachability and CPU-to-device
+/// only after a platform-selected policy proves DMA reachability and CPU-to-device
 /// visibility for the selected controller.
 pub struct DmaReadableBuffer<'a> {
     bytes: &'a [u8],