add new hardware peripheral

examples/embassy-blinky/src/main.rs

@@ -4,6 +4,7 @@
 
 use defmt::info;
 use defmt_rtt as _;
+use cortex_m as _;
 use embassy_executor::Spawner;
 use embassy_stm32::gpio::{Level, Output, Speed};
 use embassy_time::Timer;