tftp prototypes moved to tftp.h

src/include/etherboot.h

 extern char as_main_program;
 /* nic.c */
 extern void rx_qdrain P((void));
-extern int tftp P((const char *name, int (*)(unsigned char *, unsigned int, unsigned int, int)));
-extern int tftp_block P((struct tftpreq_info_t *, struct tftpblk_info_t *));
 extern int ip_transmit P((int len, const void *buf));
 extern void build_ip_hdr P((unsigned long destip, int ttl, int protocol, 
 	int option_len, int len, const void *buf));