Revert "Remove unused method"

This reverts commit bc8148b.

Author: GMagician

cores/arduino/Adafruit_TinyUSB_Core/tinyusb/src/class/cdc/cdc_device.h

@@ -82,6 +82,7 @@ static inline uint32_t tud_cdc_read            (void* buffer, uint32_t bufsize);
 static inline void     tud_cdc_read_flush      (void);
 static inline bool     tud_cdc_peek            (int pos, uint8_t* u8);
 
+static inline uint32_t tud_cdc_write_char      (char ch);
 static inline uint32_t tud_cdc_write           (void const* buffer, uint32_t bufsize);
 static inline uint32_t tud_cdc_write_str       (char const* str);
 static inline bool     tud_cdc_write_flush     (void);
@@ -167,6 +168,11 @@ static inline bool tud_cdc_peek (int pos, uint8_t* u8)
   return tud_cdc_n_peek(0, pos, u8);
 }
 
+static inline uint32_t tud_cdc_write_char (char ch)
+{
+  return tud_cdc_n_write_char(0, ch);
+}
+
 static inline uint32_t tud_cdc_write (void const* buffer, uint32_t bufsize)
 {
   return tud_cdc_n_write(0, buffer, bufsize);