stm32: move dbgmcu stuff to toplevel config setting, defaulting to true.

examples/stm32l4/src/bin/usart_dma.rs

@@ -8,7 +8,6 @@
 mod example_common;
 use core::fmt::Write;
 use embassy::executor::Spawner;
-use embassy_stm32::dbgmcu::Dbgmcu;
 use embassy_stm32::dma::NoDma;
 use embassy_stm32::usart::{Config, Uart};
 use embassy_stm32::Peripherals;
@@ -20,10 +19,6 @@ use heapless::String;
 async fn main(_spawner: Spawner, p: Peripherals) {
     info!("Hello World!");
 
-    unsafe {
-        Dbgmcu::enable_all();
-    }
-
     let config = Config::default();
     let mut usart = Uart::new(p.UART4, p.PA1, p.PA0, p.DMA1_CH3, NoDma, config);