Updated PXE UDP implementation to use the new Etherboot UDP API.

Updated PXE API dispatcher to use copy_{to,from}_user, and moved to
arch/i386 since the implementation is quite architecture-dependent.
(The individual PXE API calls can be largely
architecture-independent.)

src/interface/pxe/pxe_tftp.c

@@ -22,6 +22,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#if 0
+
 #include "pxe.h"
 
 static int pxe_tftp_read_block ( unsigned char *data, unsigned int block,
@@ -621,3 +623,5 @@ Note to future API designers at Intel: try to understand the
 underlying network protocol first!
 
 */
+
+#endif