platforms/stm32f7: remove GEPRC UART diagnostic

platforms/stm32f7/src/f722/peripherals/usart.rs

@@ -85,20 +85,6 @@ impl Usart2Tx {
         self.peripheral.tdr().as_ptr() as u32
     }
 
-    /// Blocks until USART2 accepts one byte for transmission.
-    ///
-    /// This is used by the platform's UART wire diagnostic. Flight data-channel traffic
-    /// uses [`Usart2TxDma`](super::Usart2TxDma) instead.
-    #[cfg(target_arch = "arm")]
-    pub fn write_blocking(&self, byte: u8) {
-        while !self.peripheral.isr().read().txe().is_not_full() {}
-        self.peripheral.tdr().write(|write| {
-            // SAFETY: `byte` is eight bits and therefore fits the USART's
-            // documented nine-bit TDR data field.
-            unsafe { write.tdr().bits(u16::from(byte)) }
-        });
-    }
-
     /// Acknowledges one USART2 receive interrupt without accessing TX state.
     pub fn acknowledge_receive_interrupt() -> ReceiveInterrupt {
         // SAFETY: the platform binds USART2 exactly once and this function touches