Readded misssing prototypes.

Author: joshua-beck-0908

supervisor/shared/serial.c

@@ -329,7 +329,7 @@ uint32_t serial_bytes_available(void) {
     #if CIRCUITPY_USB
     count += tud_cdc_available();
     #endif
-  
+
     // Board-specific serial input.
     count += board_serial_bytes_available();
 

supervisor/shared/serial.h

@@ -61,6 +61,10 @@ bool port_serial_connected(void);
 char port_serial_read(void);
 uint32_t port_serial_bytes_available(void);
 void port_serial_write_substring(const char *text, uint32_t length);
+void board_serial_early_init(void);
+void board_serial_init(void);
+bool board_serial_connected(void);
+char board_serial_read(void);
 uint32_t board_serial_bytes_available(void);
 void board_serial_write_substring(const char *text, uint32_t length);