stm32: update adc examples

examples/stm32f7/src/bin/adc.rs

@@ -4,7 +4,7 @@
 use defmt::*;
 use embassy_executor::Spawner;
 use embassy_stm32::adc::Adc;
-use embassy_time::{Delay, Timer};
+use embassy_time::Timer;
 use {defmt_rtt as _, panic_probe as _};
 
 #[embassy_executor::main]
@@ -12,7 +12,7 @@ async fn main(_spawner: Spawner) {
     let p = embassy_stm32::init(Default::default());
     info!("Hello World!");
 
-    let mut adc = Adc::new(p.ADC1, &mut Delay);
+    let mut adc = Adc::new(p.ADC1);
     let mut pin = p.PA3;
 
     let mut vrefint = adc.enable_vrefint();