Fix compiler warnings: sketch/uart2.c:19:33: warning: unused parameter 'stream' [-Wunused-parameter]

sketch/uart2.c:28:25: warning: unused parameter 'stream' [-Wunused-parameter]
sketch/Marlin_main.cpp:925:5: warning: unused parameter 'stream' [-Wunused-parameter]
sketch/lcd.cpp:224:5: warning: unused parameter 'stream' [-Wunused-parameter]

Firmware/Marlin_main.cpp

@@ -922,7 +922,7 @@ if((eSoundMode==e_SOUND_MODE_LOUD)||(eSoundMode==e_SOUND_MODE_ONCE))
 
 FILE _uartout; //= {0}; Global variable is always zero initialized. No need to explicitly state this.
 
-int uart_putchar(char c, FILE *stream)
+int uart_putchar(char c, FILE *)
 {
 	MYSERIAL.write(c);
 	return 0;

Firmware/lcd.cpp

@@ -221,7 +221,7 @@ static void lcd_begin(uint8_t lines, uint8_t dotsize, uint8_t clear)
 	lcd_escape[0] = 0;
 }
 
-int lcd_putchar(char c, FILE *stream)
+int lcd_putchar(char c, FILE *)
 {
 	lcd_write(c);
 	return 0;

Firmware/uart2.c

@@ -16,7 +16,7 @@ uint8_t uart2_ibuf[10] = {0, 0};
 FILE _uart2io = {0};
 
 
-int uart2_putchar(char c, FILE *stream)
+int uart2_putchar(char c, FILE *stream __attribute__((unused)))
 {
 	while (!uart2_txready);
 	UDR2 = c; // transmit byte
@@ -25,7 +25,7 @@ int uart2_putchar(char c, FILE *stream)
 	return 0;
 }
 
-int uart2_getchar(FILE *stream)
+int uart2_getchar(FILE *stream __attribute__((unused)))
 {
 	if (rbuf_empty(uart2_ibuf)) return -1;
 	return rbuf_get(uart2_ibuf);