removes dependency of board.c to libc

port/moonlight/src/board.c

@@ -2,8 +2,6 @@
 #include "csr.h"
 #include "platform.h"
 #include "uart.h"
-#include <stdio.h>
-#include <stdarg.h>
 
 // needed by picolibc/port.c
 int uart_putc(int ch) {
@@ -22,11 +20,6 @@ int uart_getc(void) {
     return ch;
 }
 
-int uart_init(void) {
-    puts("[UART0] : Uart Init Done, this is Test output!");
-    return 0;
-};
-
 int board_init(void) {
     int ret;
     ret = uart_init();