Change feature-gate for the usb module

Author: Disasm

src/lib.rs

@@ -180,7 +180,7 @@ pub mod spi;
 pub mod time;
 #[cfg(feature = "device-selected")]
 pub mod timer;
-#[cfg(any(feature = "stm32f102", feature = "stm32f103"))]
+#[cfg(all(feature = "device-selected", feature = "stm32-usbd"))]
 pub mod usb;
 #[cfg(feature = "device-selected")]
 pub mod watchdog;