Remove newlib dependency, include own stdio/string/assert

firmware/libcommon/source/fputs.c

@@ -0,0 +1,15 @@
+#include <stdio.h>
+#include "uart_console.h"
+
+int fputc(int c, FILE *stream)
+{
+	UART_PutChar(c);
+	return c;
+}
+
+int fputs(const char *s, FILE *stream)
+{
+	while (*s != '\0')
+		UART_PutChar(*s++);
+	return 0;
+}