arduino-hal: Reexport ADC types and module

Reexport the `adc` module from the HAL crate to make the ADC easily
usable.

arduino-hal/src/lib.rs

@@ -46,6 +46,18 @@ pub mod i2c {
 #[cfg(feature = "board-selected")]
 pub use i2c::I2c;
 
+#[cfg(feature = "board-selected")]
+pub mod adc {
+ pub use crate::hal::adc::{
+ channel, AdcChannel, AdcOps, AdcSettings, ClockDivider, ReferenceVoltage,
+ };
+
+ /// Check the [`avr_hal_generic::adc::Adc`] documentation.
+ pub type Adc = crate::hal::Adc<crate::DefaultClock>;
+}
+#[cfg(feature = "board-selected")]
+pub use adc::Adc;
+
 #[cfg(feature = "board-selected")]
 pub mod usart {
  pub use crate::hal::usart::{Baudrate, UsartOps};