refactor MAC auth

pn532/src/driver.rs

@@ -8,6 +8,7 @@ use core::time::Duration;
 
 /// A card UID read by [`Pn532::read_passive_target_id`].
 #[derive(Debug, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct Uid {
     pub bytes: heapless::Vec<u8, 7>,
 }
@@ -25,15 +26,9 @@ impl core::fmt::Display for Uid {
     }
 }
 
-#[cfg(feature = "defmt")]
-impl defmt::Format for Uid {
-    fn format(&self, fmt: defmt::Formatter) {
-        defmt::write!(fmt, "{}", defmt::Display2Format(self));
-    }
-}
-
 /// Outcome of [`Pn532::tg_init_as_target`] / [`Pn532::tg_init_as_target_default`].
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum TargetInitStatus {
     /// The PN532 entered target mode.
     Success,